1. Lavington S (April/June 2006) In the footsteps of Colossus; a description of Oedipus. IEEE Ann Hist Comput 28(2):44–55. Invaluable help with the preparation of this paper was given to the author by Tony R (especially in a letter to Simon Lavington dated 16 July 2002) and by Peter Freeman (especially in a letter to Simon Lavington dated 2 Dec 2002)
2. Bunt JP. The 153 computer. Volume 1. Borehamwood Internal report 371(A), dated 1 Jan 1956. The diagrams are bound separately as Volume 2, report 371(B), also dated 1 Jan 1956. Volume 3, report 371(C) of the same date, contains test programs. Some amendments to report 371 were dated 30 Sept 1957. A related report by John Bunt is entitled: 153 computer maintenance handbook. Borehamwood Internal report 386, dated 1 Oct 1955
3. Bambrough B (1951) Design proposals for D/F calculator. Borehamwood Internal report 246, dated 29 July 1951
4. Anon (2001) Unsigned one-page typed note, attached to a letter dated 2 Oct 2001 from Gill Bennett, Chief Historian, Foreign and Commonwealth Office, to Simon Lavington. It is assumed that the source of the attached note was GCHQ
5. John Bunt (2002) The history of the 153. Two-page typed manuscript, sent to Simon Lavington with an accompanying letter dated 13 May 2002