We begin with the locations of the archives where major collections are held, usually the surviving Nachlass of a figure; unless otherwise indicated in brackets, a collection is held in the University library or archive of the institution named. Collections are not noted for figures whose roles in the story have been marginal (for example, Bolzano and Lagrange).
Cambridge (England): Hawtrey (Churchill College); G. E. Moore, Turnbull (University); Newman (St. John’s College); Venn (Gonville and Caius College); University Press records.
Chichester (England), West Sussex Record Office: Kempe.
Djursholm (Sweden), Institut Mittag-Leffler: Jourdain, Mittag-Leffler.
Englefield Green (England), Royal Holloway College: ...