The close back protruded vowel is the most common variant of the close back rounded vowel. It is typically transcribed in IPA simply as ⟨u⟩ (the convention used in this article). As there is no dedicated IPA diacritic for protrusion, the symbol for the close back rounded vowel with an old diacritic for labialization, ⟨ ̫⟩, can be used as an ad hoc symbol ⟨u̫⟩. Another possible transcription is ⟨uʷ⟩ or ⟨ɯʷ⟩ (a close back vowel modified by endolabialization), but that could be misread as a diphthong.
While the International Phonetic Association prefers the terms "close" and "open" for vowel height, many linguists use "high" and "low". /wiki/International_Phonetic_Association
Donaldson (1993), pp. 2, 5. - Donaldson, Bruce C. (1993), "1. Pronunciation", A Grammar of Afrikaans, Mouton de Gruyter, pp. 1–35, ISBN 9783110134261 https://books.google.com/books?id=ftzioRvJzTUC
Donaldson (1993), p. 5. - Donaldson, Bruce C. (1993), "1. Pronunciation", A Grammar of Afrikaans, Mouton de Gruyter, pp. 1–35, ISBN 9783110134261 https://books.google.com/books?id=ftzioRvJzTUC
Thelwall & Sa'Adeddin (1990), p. 38. - Thelwall, Robin; Sa'Adeddin, M. Akram (1990), "Arabic", Journal of the International Phonetic Association, 20 (2): 37–39, doi:10.1017/S0025100300004266, S2CID 243640727 https://doi.org/10.1017%2FS0025100300004266
Dum-Tragut (2009), p. 13. - Dum-Tragut, Jasmine (2009), Armenian: Modern Eastern Armenian, Amsterdam: John Benjamins Publishing Company
Traunmüller (1982), cited in Ladefoged & Maddieson (1996:290) - Traunmüller, Hartmut (1982), "Vokalismus in der westniederösterreichischen Mundart.", Zeitschrift für Dialektologie und Linguistik, 2: 289–333
Traunmüller (1982), cited in Ladefoged & Maddieson (1996:290) - Traunmüller, Hartmut (1982), "Vokalismus in der westniederösterreichischen Mundart.", Zeitschrift für Dialektologie und Linguistik, 2: 289–333
Ternes & Vladimirova-Buhtz (1999), p. 56. - Ternes, Elmer; Vladimirova-Buhtz, Tatjana (1999), "Bulgarian", Handbook of the International Phonetic Association, Cambridge University Press, pp. 55–57, ISBN 978-0-521-63751-0 https://books.google.com/books?id=33BSkFV_8PEC&pg=PA55
Carbonell & Llisterri (1992), p. 54. - Carbonell, Joan F.; Llisterri, Joaquim (1992), "Catalan", Journal of the International Phonetic Association, 22 (1–2): 53–56, doi:10.1017/S0025100300004618, S2CID 249411809 https://doi.org/10.1017%2FS0025100300004618
Lee & Zee (2003), pp. 110–111. - Lee, Wai-Sum; Zee, Eric (2003), "Standard Chinese (Beijing)", Journal of the International Phonetic Association, 33 (1): 109–112, doi:10.1017/S0025100303001208 https://doi.org/10.1017%2FS0025100303001208
Duanmu (2007), pp. 35–36. - Duanmu, San (2007) [First published 2000], The Phonology of Standard Chinese (2nd ed.), Oxford: Oxford University Press, ISBN 978-0-19-921578-2
Zee (1999), pp. 59–60. - Zee, Eric (1999), "Chinese (Hong Kong Cantonese)", Handbook of the International Phonetic Association: A guide to the use of the International Phonetic Alphabet, Cambridge: Cambridge University Press, pp. 58–60, ISBN 978-0-521-65236-0
Chen & Gussenhoven (2015), pp. 328–329. - Chen, Yiya; Gussenhoven, Carlos (2015), "Shanghai Chinese", Journal of the International Phonetic Association, 45 (3): 321–327, doi:10.1017/S0025100315000043 https://www.researchgate.net/publication/287375585
Chen & Gussenhoven (2015), pp. 328–329. - Chen, Yiya; Gussenhoven, Carlos (2015), "Shanghai Chinese", Journal of the International Phonetic Association, 45 (3): 321–327, doi:10.1017/S0025100315000043 https://www.researchgate.net/publication/287375585
Grønnum (1998), p. 100. - Grønnum, Nina (1998), "Illustrations of the IPA: Danish", Journal of the International Phonetic Association, 28 (1 & 2): 99–105, doi:10.1017/s0025100300006290, S2CID 249412109 https://doi.org/10.1017%2Fs0025100300006290
Basbøll (2005), p. 46. - Basbøll, Hans (2005), The Phonology of Danish, Taylor & Francis, ISBN 978-0-203-97876-4
Gussenhoven (1992), p. 47. - Gussenhoven, Carlos (1992), "Dutch", Journal of the International Phonetic Association, 22 (2): 45–47, doi:10.1017/S002510030000459X, S2CID 243772965 https://doi.org/10.1017%2FS002510030000459X
Verhoeven (2005), p. 245. - Verhoeven, Jo (2005), "Belgian Standard Dutch", Journal of the International Phonetic Association, 35 (2): 243–247, doi:10.1017/S0025100305002173 https://doi.org/10.1017%2FS0025100305002173
Verhoeven (2005), p. 245. - Verhoeven, Jo (2005), "Belgian Standard Dutch", Journal of the International Phonetic Association, 35 (2): 243–247, doi:10.1017/S0025100305002173 https://doi.org/10.1017%2FS0025100305002173
Cox & Palethorpe (2007), p. 344. - Cox, Felicity; Palethorpe, Sallyanne (2007), "Australian English", Journal of the International Phonetic Association, 37 (3): 341–350, doi:10.1017/S0025100307003192 https://doi.org/10.1017%2FS0025100307003192
Cox & Fletcher (2017), p. 65. - Cox, Felicity; Fletcher, Janet (2017) [First published 2012], Australian English Pronunciation and Transcription (2nd ed.), Cambridge University Press, ISBN 978-1-316-63926-9 https://books.google.com/books?id=ZBs3DwAAQBAJ
Finn (2004), p. 970. - Finn, Peter (2004), "Cape Flats English: phonology", in Schneider, Edgar W.; Burridge, Kate; Kortmann, Bernd; Mesthrie, Rajend; Upton, Clive (eds.), A handbook of varieties of English, vol. 1: Phonology, Mouton de Gruyter, pp. 964–984, ISBN 978-3-11-017532-5
Finn (2004), p. 970. - Finn, Peter (2004), "Cape Flats English: phonology", in Schneider, Edgar W.; Burridge, Kate; Kortmann, Bernd; Mesthrie, Rajend; Upton, Clive (eds.), A handbook of varieties of English, vol. 1: Phonology, Mouton de Gruyter, pp. 964–984, ISBN 978-3-11-017532-5
Lass (2002), p. 116. - Lass, Roger (2002), "South African English", in Mesthrie, Rajend (ed.), Language in South Africa, Cambridge University Press, ISBN 9780521791052
Mannell, Cox & Harrington (2009). - Mannell, R.; Cox, F.; Harrington, J. (2009), An Introduction to Phonetics and Phonology, Macquarie University http://clas.mq.edu.au/speech/phonetics/phonetics/vowelgraphs/AusE_Monophthongs.html
Watt & Allen (2003), p. 268. - Watt, Dominic; Allen, William (2003), "Tyneside English", Journal of the International Phonetic Association, 33 (2): 267–271, doi:10.1017/S0025100303001397 https://doi.org/10.1017%2FS0025100303001397
Raymond Hickey (2004). Bernd Kortmann and Edgar W. Schneider (ed.). A Handbook of Varieties of English Volume 1: Phonology. De Gruyter. p. 91.
Cruttenden (2014), p. 91. - Cruttenden, Alan (2014), Gimson's Pronunciation of English (8th ed.), Routledge, ISBN 9781444183092 https://books.google.com/books?id=M2nMAgAAQBAJ
Roach (2004), p. 242. - Roach, Peter (2004), "British English: Received Pronunciation", Journal of the International Phonetic Association, 34 (2): 239–245, doi:10.1017/S0025100304001768 https://doi.org/10.1017%2FS0025100304001768
Collins & Mees (1990), p. 95. - Collins, Beverley; Mees, Inger M. (1990), "The Phonetics of Cardiff English", in Coupland, Nikolas; Thomas, Alan Richard (eds.), English in Wales: Diversity, Conflict, and Change, Multilingual Matters Ltd., pp. 87–103, ISBN 978-1-85359-032-0 https://books.google.com/books?id=tPwYt3gVbu4C
Connolly (1990), p. 125. - Connolly, John H. (1990), "Port Talbot English", in Coupland, Nikolas; Thomas, Alan Richard (eds.), English in Wales: Diversity, Conflict, and Change, Multilingual Matters Ltd., pp. 121–129, ISBN 978-1-85359-032-0 https://books.google.com/books?id=tPwYt3gVbu4C
Tench (1990), p. 135. - Tench, Paul (1990), "The Pronunciation of English in Abercrave", in Coupland, Nikolas; Thomas, Alan Richard (eds.), English in Wales: Diversity, Conflict, and Change, Multilingual Matters Ltd., pp. 130–141, ISBN 978-1-85359-032-0 https://books.google.com/books?id=tPwYt3gVbu4C
Mahboob & Ahmar (2004), p. 1007. - Mahboob, Ahmar; Ahmar, Nadra H. (2004), "Pakistani English: phonology", in Schneider, Edgar W. (ed.), A handbook of varieties of English, vol. 1, Berlin; New York: Mouton de Gruyter, pp. 1003–1015 https://www.academia.edu/816224
Raymond Hickey (2004). Bernd Kortmann and Edgar W. Schneider (ed.). A Handbook of Varieties of English Volume 1: Phonology. De Gruyter. p. 287.
Labov, William; Ash, Sharon; Boberg, Charles (2006). The Atlas of North American English. chpt. 17
"NZE Phonology" (PDF). Victoria University of Wellington. p. 3. http://www.victoria.ac.nz/lals/research/projects/grinze-archived/publications/NZE_PhonologyPW.pdf
Bauer & Warren (2004), p. 585. - Bauer, Laurie; Warren, Paul (2004), "New Zealand English: phonology", in Schneider, Edgar W.; Burridge, Kate; Kortmann, Bernd; Mesthrie, Rajend; Upton, Clive (eds.), A handbook of varieties of English, vol. 1: Phonology, Mouton de Gruyter, pp. 580–602, ISBN 978-3-11-017532-5
"NZE Phonology" (PDF). Victoria University of Wellington. p. 3. http://www.victoria.ac.nz/lals/research/projects/grinze-archived/publications/NZE_PhonologyPW.pdf
Bauer & Warren (2004), p. 585. - Bauer, Laurie; Warren, Paul (2004), "New Zealand English: phonology", in Schneider, Edgar W.; Burridge, Kate; Kortmann, Bernd; Mesthrie, Rajend; Upton, Clive (eds.), A handbook of varieties of English, vol. 1: Phonology, Mouton de Gruyter, pp. 580–602, ISBN 978-3-11-017532-5
Asu & Teras (2009), p. 368. - Asu, Eva Liina; Teras, Pire (2009), "Estonian", Journal of the International Phonetic Association, 39 (3): 367–372, doi:10.1017/s002510030999017x https://doi.org/10.1017%2Fs002510030999017x
Iivonen & Harnud (2005), pp. 60, 66. - Iivonen, Antti; Harnud, Huhe (2005), "Acoustical comparison of the monophthong systems in Finnish, Mongolian and Udmurt", Journal of the International Phonetic Association, 35 (1): 59–71, doi:10.1017/S002510030500191X, S2CID 145733117 https://doi.org/10.1017%2FS002510030500191X
Suomi, Toivanen & Ylitalo (2008), p. 21. - Suomi, Kari; Toivanen, Juhani; Ylitalo, Riikka (2008), Finnish sound structure – Phonetics, phonology, phonotactics and prosody (PDF), Studia Humaniora Ouluensia 9, Oulu University Press, ISBN 978-951-42-8984-2 http://jultika.oulu.fi/files/isbn9789514289842.pdf
Árnason (2011), pp. 68, 74. - Árnason, Kristján (2011), The Phonology of Icelandic and Faroese, Oxford University Press, ISBN 978-0-19-922931-4
Fougeron & Smith (1993), p. 73. - Fougeron, Cecile; Smith, Caroline L (1993), "French", Journal of the International Phonetic Association, 23 (2): 73–76, doi:10.1017/S0025100300004874, S2CID 249404451 https://doi.org/10.1017%2FS0025100300004874
Collins & Mees (2013), p. 225. - Collins, Beverley; Mees, Inger M. (2013) [First published 2003], Practical Phonetics and Phonology: A Resource Book for Students (3rd ed.), Routledge, ISBN 978-0-415-50650-2 https://books.google.com/books?id=faVJTQIw9eQC
Shosted & Chikovani (2006), pp. 261–262. - Shosted, Ryan K.; Chikovani, Vakhtang (2006), "Standard Georgian" (PDF), Journal of the International Phonetic Association, 36 (2): 255–264, doi:10.1017/S0025100306002659 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/A7DCF9606BA856FCA5CC25918ADB37EF/S0025100306002659a.pdf/standard_georgian.pdf
Hall (2003), pp. 87, 107. - Hall, Christopher (2003) [First published 1992], Modern German pronunciation: An introduction for speakers of English (2nd ed.), Manchester: Manchester University Press, ISBN 978-0-7190-6689-4
Dudenredaktion, Kleiner & Knöbl (2015), p. 34. - Dudenredaktion; Kleiner, Stefan; Knöbl, Ralf (2015) [First published 1962], Das Aussprachewörterbuch (in German) (7th ed.), Berlin: Dudenverlag, ISBN 978-3-411-04067-4 https://books.google.com/books?id=T6vWCgAAQBAJ
Dudenredaktion, Kleiner & Knöbl (2015), p. 64. - Dudenredaktion; Kleiner, Stefan; Knöbl, Ralf (2015) [First published 1962], Das Aussprachewörterbuch (in German) (7th ed.), Berlin: Dudenverlag, ISBN 978-3-411-04067-4 https://books.google.com/books?id=T6vWCgAAQBAJ
Dudenredaktion, Kleiner & Knöbl (2015), p. 64. - Dudenredaktion; Kleiner, Stefan; Knöbl, Ralf (2015) [First published 1962], Das Aussprachewörterbuch (in German) (7th ed.), Berlin: Dudenverlag, ISBN 978-3-411-04067-4 https://books.google.com/books?id=T6vWCgAAQBAJ
Arvaniti (2007), p. 28. - Arvaniti, Amalia (2007), "Greek Phonetics: The State of the Art", Journal of Greek Linguistics, 8: 97–208, CiteSeerX 10.1.1.692.1365, doi:10.1075/jgl.8.08arv https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.692.1365
Trudgill (2009), p. 81. - Trudgill, Peter (2009), "Greek Dialect Vowel Systems, Vowel Dispersion Theory, and Sociolinguistic Typology", Journal of Greek Linguistics, 9 (1): 80–97, doi:10.1163/156658409X12500896406041 https://www.researchgate.net/publication/233523754
Szende (1994), p. 92. - Szende, Tamás (1994), "Hungarian", Journal of the International Phonetic Association, 24 (2): 91–94, doi:10.1017/S0025100300005090, S2CID 242632087 https://doi.org/10.1017%2FS0025100300005090
Árnason (2011), p. 60. - Árnason, Kristján (2011), The Phonology of Icelandic and Faroese, Oxford University Press, ISBN 978-0-19-922931-4
Einarsson (1945:10), cited in Gussmann (2011:73) - Einarsson, Stefán (1945), Icelandic. Grammar texts glossary., Baltimore: The Johns Hopkins Press, ISBN 978-0801863578
"Indonesian Alphabet and Pronunciation". mylanguages.org. Retrieved 2021-05-17. http://mylanguages.org/indonesian_alphabet.php
Rogers & d'Arcangeli (2004), p. 119. - Rogers, Derek; d'Arcangeli, Luciana (2004), "Italian", Journal of the International Phonetic Association, 34 (1): 117–121, doi:10.1017/S0025100304001628 https://doi.org/10.1017%2FS0025100304001628
Jolkesky (2009), pp. 676–677, 682. - Jolkesky, Marcelo Pinho de Valhery (2009), "Fonologia e prosódia do Kaingáng falado em Cacique Doble", Anais do SETA, 3, Campinas: 675–685 http://www.iel.unicamp.br/revista/index.php/seta/article/view/557/474
Thackston (2006a), p. 1. - Thackston, W.M. (2006a), —Sorani Kurdish— A Reference Grammar with Selected Readings (PDF), archived from the original (PDF) on 27 February 2021, retrieved 29 October 2017 https://web.archive.org/web/20210227111912/https://sites.fas.harvard.edu/~iranian/Sorani/sorani_1_grammar.pdf
Khan & Lescot (1970), pp. 8–16. - Khan, Celadet Bedir; Lescot, Roger (1970), Grammaire Kurde (Dialecte kurmandji) (PDF), Paris: La librairie d'Amérique et d'Orient Adrien Maisonneuve, retrieved 28 October 2017 http://tirsik.net/danegeh/pirtuk/celadet_ali_bedirxan/Grammaire%20kurde%20(Dialecte%20kurmandji).pdf
Fattah describes the sound as being voyelle longue centrale arrondie (p. 116).
Wheelock's Latin (1956). - Wheelock, Frederick M.; LaFleur, Richard A. (2011) [1956]. Wheelock's Latin (Seventh ed.). HarperCollins. ISBN 978-0-06-199722-8.
Gussenhoven & Aarts (1999), p. 159. - Gussenhoven, Carlos; Aarts, Flor (1999), "The dialect of Maastricht" (PDF), Journal of the International Phonetic Association, 29 (2): 155–166, doi:10.1017/S0025100300006526, S2CID 145782045 http://gep.ruhosting.nl/carlos/gussenhoven_aarts.pdf
Peters (2006), p. 119. - Peters, Jörg (2006), "The dialect of Hasselt", Journal of the International Phonetic Association, 36 (1): 117–124, doi:10.1017/S0025100306002428 https://doi.org/10.1017%2FS0025100306002428
Peters (2006), p. 119. - Peters, Jörg (2006), "The dialect of Hasselt", Journal of the International Phonetic Association, 36 (1): 117–124, doi:10.1017/S0025100306002428 https://doi.org/10.1017%2FS0025100306002428
Gussenhoven & Aarts (1999), p. 159. - Gussenhoven, Carlos; Aarts, Flor (1999), "The dialect of Maastricht" (PDF), Journal of the International Phonetic Association, 29 (2): 155–166, doi:10.1017/S0025100300006526, S2CID 145782045 http://gep.ruhosting.nl/carlos/gussenhoven_aarts.pdf
Stone (2002), p. 600. - Stone, Gerald (2002), "Sorbian (Upper and Lower)", in Comrie, Bernard; Corbett, Greville G. (eds.), The Slavonic Languages, London and New York: Routledge, pp. 593–685, ISBN 9780415280785
Gilles & Trouvain (2013), p. 70. - Gilles, Peter; Trouvain, Jürgen (2013), "Luxembourgish", Journal of the International Phonetic Association, 43 (1): 67–74, doi:10.1017/S0025100312000278 https://doi.org/10.1017%2FS0025100312000278
Iivonen & Harnud (2005), pp. 62, 66–67. - Iivonen, Antti; Harnud, Huhe (2005), "Acoustical comparison of the monophthong systems in Finnish, Mongolian and Udmurt", Journal of the International Phonetic Association, 35 (1): 59–71, doi:10.1017/S002510030500191X, S2CID 145733117 https://doi.org/10.1017%2FS002510030500191X
Allison (2006). - Allison, Sean (2006), Alphabet et orthographe de Kotoko de Makary (mpadɨ) (Makary Kotoko Orthography Statement), SIL http://www.silcam.org/resources/archives/32321
Jassem (2003), p. 105. - Jassem, Wiktor (2003), "Polish", Journal of the International Phonetic Association, 33 (1): 103–107, doi:10.1017/S0025100303001191 https://doi.org/10.1017%2FS0025100303001191
Cruz-Ferreira (1995), p. 91. - Cruz-Ferreira, Madalena (1995), "European Portuguese" (PDF), Journal of the International Phonetic Association, 25 (2): 90–94, doi:10.1017/S0025100300005223, S2CID 249414876 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/0A8156D240CCB941A73C4C0EC1672A19/S0025100300005223a.pdf/european-portuguese.pdf
Sarlin (2014), p. 18. - Sarlin, Mika (2014) [First published 2013], "Sounds of Romanian and their spelling", Romanian Grammar (2nd ed.), Helsinki: Books on Demand GmbH, pp. 16–37, ISBN 978-952-286-898-5 https://books.google.com/books?id=nKWpBAAAQBAJ
Jones & Ward (1969), p. 67. - Jones, Daniel; Ward, Dennis (1969), The Phonetics of Russian, Cambridge University Press
"Aspiration". Scottish Gaelic Dialect Survey. Archived from the original on 2021-04-24. Retrieved 2021-04-23. https://doug5181.wixsite.com/sgdsmaps/page9
Oftedal (1956), p. 75–76. - Oftedal, Magne (1956), The Gaelic of Leurbost, Isle of Lewis (PDF), Norsk Tidskrift for Sprogvidenskap https://www.alastairmcintosh.com/general/resources/1956-Magne-Oftedal-Leurbost-Gaelic.pdf
Landau et al. (1999), p. 67. - Landau, Ernestina; Lončarića, Mijo; Horga, Damir; Škarić, Ivo (1999), "Croatian", Handbook of the International Phonetic Association: A guide to the use of the International Phonetic Alphabet, Cambridge: Cambridge University Press, pp. 66–69, ISBN 978-0-521-65236-0
Fast Mowitz (1975), p. 2. - Fast Mowitz, Gerhard (1975), Sistema fonológico del idioma achual, Lima: Instituto Lingüístico de Verano
Martínez-Celdrán, Fernández-Planas & Carrera-Sabaté (2003), p. 256. - Martínez-Celdrán, Eugenio; Fernández-Planas, Ana Ma.; Carrera-Sabaté, Josefina (2003), "Castilian Spanish", Journal of the International Phonetic Association, 33 (2): 255–259, doi:10.1017/S0025100303001373 https://doi.org/10.1017%2FS0025100303001373
Doke & Mofokeng (1974), p. ?. - Doke, Clement Martyn; Mofokeng, S. Machabe (1974), Textbook of Southern Sotho Grammar (3rd ed.), Cape Town: Longman Southern Africa, ISBN 978-0-582-61700-1
Doke & Mofokeng (1974), p. ?. - Doke, Clement Martyn; Mofokeng, S. Machabe (1974), Textbook of Southern Sotho Grammar (3rd ed.), Cape Town: Longman Southern Africa, ISBN 978-0-582-61700-1
Tingsabadh & Abramson (1993), p. 24. - Tingsabadh, M. R. Kalaya; Abramson, Arthur S. (1993), "Thai", Journal of the International Phonetic Association, 23 (1): 24–28, doi:10.1017/S0025100300004746, S2CID 242001518 https://doi.org/10.1017%2FS0025100300004746
Zimmer & Orgun (1999), p. 155. - Zimmer, Karl; Orgun, Orhan (1999), "Turkish" (PDF), Handbook of the International Phonetic Association: A guide to the use of the International Phonetic Alphabet, Cambridge: Cambridge University Press, pp. 154–158, ISBN 978-0-521-65236-0, archived from the original (PDF) on 2018-07-25, retrieved 2015-11-20 https://web.archive.org/web/20180725111322/http://www.uta.edu/faculty/cmfitz/swnal/projects/CoLang/courses/Transcription/rosettaproject_tur_phon-2.pdf
Göksel & Kerslake (2005), p. 11. - Göksel, Asli; Kerslake, Celia (2005), Turkish: a comprehensive grammar, Routledge, ISBN 978-0415114943
Iivonen & Harnud (2005), pp. 64, 68. - Iivonen, Antti; Harnud, Huhe (2005), "Acoustical comparison of the monophthong systems in Finnish, Mongolian and Udmurt", Journal of the International Phonetic Association, 35 (1): 59–71, doi:10.1017/S002510030500191X, S2CID 145733117 https://doi.org/10.1017%2FS002510030500191X
Danyenko & Vakulenko (1995), p. 4. - Danyenko, Andrii; Vakulenko, Serhii (1995), Ukrainian, Lincom Europa, ISBN 9783929075083 https://books.google.com/books?id=WUsbAQAAIAAJ
Stone (2002), p. 600. - Stone, Gerald (2002), "Sorbian (Upper and Lower)", in Comrie, Bernard; Corbett, Greville G. (eds.), The Slavonic Languages, London and New York: Routledge, pp. 593–685, ISBN 9780415280785
Šewc-Schuster (1984), p. 20. - Šewc-Schuster, Hinc (1984), Gramatika hornjo-serbskeje rěče, Budyšin: Ludowe nakładnistwo Domowina
Bamgboṣe (1966), p. 166. - Bamgboṣe, Ayọ (1966), A Grammar of Yoruba, [West African Languages Survey / Institute of African Studies], Cambridge: Cambridge University Press
Merrill (2008), p. 109. - Merrill, Elizabeth (2008), "Tilquiapan Zapotec" (PDF), Journal of the International Phonetic Association, 38 (1): 107–114, doi:10.1017/S0025100308003344 http://www.balsas-nahuatl.org/mixtec/Christian_articles/Otomanguean/Merrill.pdf
Ladefoged & Maddieson (1996), p. 295. - Ladefoged, Peter; Maddieson, Ian (1996), The Sounds of the World's Languages, Oxford: Blackwell, ISBN 978-0-631-19814-7
Chen & Gussenhoven (2015), pp. 328–329. - Chen, Yiya; Gussenhoven, Carlos (2015), "Shanghai Chinese", Journal of the International Phonetic Association, 45 (3): 321–327, doi:10.1017/S0025100315000043 https://www.researchgate.net/publication/287375585
Chen & Gussenhoven (2015), pp. 328–329. - Chen, Yiya; Gussenhoven, Carlos (2015), "Shanghai Chinese", Journal of the International Phonetic Association, 45 (3): 321–327, doi:10.1017/S0025100315000043 https://www.researchgate.net/publication/287375585
Chen & Gussenhoven (2015), pp. 328–329. - Chen, Yiya; Gussenhoven, Carlos (2015), "Shanghai Chinese", Journal of the International Phonetic Association, 45 (3): 321–327, doi:10.1017/S0025100315000043 https://www.researchgate.net/publication/287375585
Okada (1999), p. 118. - Okada, Hideo (1999), "Japanese", in International Phonetic Association (ed.), Handbook of the International Phonetic Association: A Guide to the Use of the International Phonetic Alphabet, Cambridge University Press, pp. 117–119, ISBN 978-0-52163751-0 https://archive.org/details/rosettaproject_jpn_phon-2
Okada (1999), p. 118. - Okada, Hideo (1999), "Japanese", in International Phonetic Association (ed.), Handbook of the International Phonetic Association: A Guide to the Use of the International Phonetic Alphabet, Cambridge University Press, pp. 117–119, ISBN 978-0-52163751-0 https://archive.org/details/rosettaproject_jpn_phon-2
Chirkova & Chen (2013), p. 78. - Chirkova, Katia; Chen, Yiya (2013), "Lizu", Journal of the International Phonetic Association, 43 (1): 75–86, doi:10.1017/S0025100312000242 https://doi.org/10.1017%2FS0025100312000242
Chirkova & Chen (2013), p. 78. - Chirkova, Katia; Chen, Yiya (2013), "Lizu", Journal of the International Phonetic Association, 43 (1): 75–86, doi:10.1017/S0025100312000242 https://doi.org/10.1017%2FS0025100312000242
Vanvik (1979), pp. 13, 17. - Vanvik, Arne (1979), Norsk fonetikk, Oslo: Universitetet i Oslo, ISBN 978-82-990584-0-7
While Vanvik (1979) does not describe the exact type of rounding of this vowel, some other sources (e.g. Haugen (1974:40) and Kristoffersen (2000:16)) state explicitly that it is compressed. - Vanvik, Arne (1979), Norsk fonetikk, Oslo: Universitetet i Oslo, ISBN 978-82-990584-0-7
Vanvik (1979), p. 17. - Vanvik, Arne (1979), Norsk fonetikk, Oslo: Universitetet i Oslo, ISBN 978-82-990584-0-7
Engstrand (1999), p. 140. - Engstrand, Olle (1999), "Swedish", Handbook of the International Phonetic Association: A Guide to the usage of the International Phonetic Alphabet., Cambridge: Cambridge University Press, pp. 140–142, ISBN 978-0-521-63751-0 https://books.google.com/books?id=33BSkFV_8PEC&pg=PA140
Rosenqvist (2007), p. 9. - Rosenqvist, Håkan (2007), Uttalsboken: svenskt uttal i praktik och teori, Stockholm: Natur & Kultur, ISBN 978-91-27-40645-2
Engstrand (1999), p. 140. - Engstrand, Olle (1999), "Swedish", Handbook of the International Phonetic Association: A Guide to the usage of the International Phonetic Alphabet., Cambridge: Cambridge University Press, pp. 140–142, ISBN 978-0-521-63751-0 https://books.google.com/books?id=33BSkFV_8PEC&pg=PA140