Howlett, Jack. "Computing at Harwell". Retrieved 2008-12-07. http://www.chilton-computing.org.uk/acl/literature/reports/p009.htm
Cooke-Yarborough, E. H. (1957). Introduction to Transistor Circuits. Edinburgh: Oliver and Boyd. p. 139.
Cooke-Yarborough, E. H. (1998). "Some early transistor applications in the UK". Engineering Science & Education Journal. 7 (3): 100–106. doi:10.1049/esej:19980301 (inactive 7 December 2024).{{cite journal}}: CS1 maint: DOI inactive as of December 2024 (link) /wiki/Doi_(identifier)
Lavington, Simon (1980). Early British Computers. Manchester University Press. p. 139. ISBN 0-7190-0803-4. 0-7190-0803-4
Cooke-Yarborough, E. H.; Barnes, R. C. M.; Stephen, J. H.; Howells, G. A. (1956). "A transistor digital computer". Proceedings of the IEE - Part B: Radio and Electronic Engineering. 103 (3S): 364–370. doi:10.1049/pi-b-1.1956.0076. /wiki/Doi_(identifier)
Cooke-Yarborough, E. H. (1998). "Some early transistor applications in the UK". Engineering Science & Education Journal. 7 (3): 100–106. doi:10.1049/esej:19980301 (inactive 7 December 2024).{{cite journal}}: CS1 maint: DOI inactive as of December 2024 (link) /wiki/Doi_(identifier)
Irvine, M. M. (2001). "Early digital computers at Bell Telephone Laboratories". IEEE Annals of the History of Computing. 23 (3): 22–42. doi:10.1109/85.948904. /wiki/Doi_(identifier)
IBM Archives, 1955 https://web.archive.org/web/20050117192557/http://www-03.ibm.com/ibm/history/history/year_1955.html
IBM Archives: IBM 608 calculator https://web.archive.org/web/20050122185954/http://www-03.ibm.com/ibm/history/exhibits/vintage/vintage_4506VV2214.html