We are planning a sequel... The Geometry of Low-Dimensional Groups and Lattices which will contain two earlier papers...
Source, in full
Ref: John H. Conway, Complex and integral laminated lattices, TAMS 280 (1983) 463-490 [2,6,22]; John H. Conway, The Coxeter–Todd lattice, The Mitchell group, and related sphere packings PCPS 93 (1983) 421-440 [2,4,7,8,22]