Chisholm, Hugh, ed. (1911). "Back-Choir" . Encyclopædia Britannica. Vol. 3 (11th ed.). Cambridge University Press. /wiki/Hugh_Chisholm
"Retrochoir". Merriam-Webster. 2015. Retrieved 8 September 2015. Definition of Retrochoir 1: the space left in a church behind the high altar or choir enclosure sometimes used as a chapel and occasionally containing a second choir enclosure http://www.merriam-webster.com/dictionary/retrochoir
"Our Heritage » Our History » Building the Cathedral". Winchester Cathedral. Retrieved 17 December 2019. https://www.winchester-cathedral.org.uk/our-heritage/our-history/building-the-cathedral/