- FondsJeffreysB - Papers of Bertha Jeffreys
- SeriesE - Lectures
- SubseriesE54-E91 - Public and invitation lectures
- FileE78-E83 - 'Augustus de Morgan. New Pythagoreans 1978'
- ItemE78 - Correspondence re de Morgan, the four-colour problem and Jeffreys's lecture
- ItemE79 - Letter by Jeffreys on Augustus de Morgan and the four-colour problem, Mathematical Gazette, June 1979
- ItemE80 - Manuscript lecture notes on de Morgan
- ItemE81-E83 - Background information on de Morgan: manuscript note