On algebraic tori of norm type.
On certain closed subgroups of .
On mutual commutants of generalized carpet subgroups.
On normal subgroups of over rings with many units
On overgroups of and in their minimal representations.
On subgroups of GL2 over non-commutative local rings which are normalized by elementary matrices.
On symplectic groups over polynomial rings.
On the congruence subgroup problem, II.
On the Congruence Subgroups Problem: Determination of the "Metaplectic Kernel".
On the group .
On the group S L 2 over orders of arithmetic type.
On the Homomorphisms of the Integral Linear Groups.
On the regular Sylow -subgroups of Chevalley groups over .
On the Schur Multipliers of Steinberg and Chevalley Groups over Commutative Rings.