  In this paper we finish the intensive study of three-dimensional Dirichlet
stereohedra started by the second author and D. Bochis, who showed that they
cannot have more than 80 facets, except perhaps for crystallographic space
groups in the cubic system.
  Taking advantage of the recent, simpler classification of three-dimensional
crystallographic groups by Conway, Delgado-Friedrichs, Huson and Thurston, in a
previous paper we proved that Dirichlet stereohedra for any of the 27 "full"
cubic groups cannot have more than 25 facets. Here we study the remaining
"quarter" cubic groups. With a computer-assisted method, our main result is
that Dirichlet stereohedra for the 8 quarter groups, hence for all
three-dimensional crystallographic groups, cannot have more than 92 facets.
