1. Harald Gottschalk and Dimitri Leemans, The residually weakly primitive geometries of the Janko group J1, Groups and Geometries (Siena, 1996), Trends Math., Birkhäuser, Basel, 1998, pp. 65–79.[MR]
  2. Harald Gottschalk and Dimitri Leemans, Geometries for the group PSL(3,4), European J. Combin. 24 (2003), no. 3, 267–291.[MR]