The normality of closures of conjugacy classes of matrices. Stephen Donkin — 1990 Inventiones mathematicae
A note on the characters of the projective modules for the infinitesimal subgroups of a semisimple algebraic group. Stephen Donkin — 1982 Mathematica Scandinavica
Polycyclic groups, Lie algebras and algebraic groups. Stephen Donkin — 1981 Journal für die reine und angewandte Mathematik