%0 Journal Article
%A Alexander J. Hahn
%T On the isomorphisms of the projective orthogonal groups and their congruence subgroups.
%J Journal für die reine und angewandte Mathematik
%D 1975
%P 1-22
%V 273
%I mathdoc
%U http://geodesic.mathdoc.fr/item/JRAM_1975__273_151535/
%F JRAM_1975__273_151535