%0 Journal Article %A Opolka, Hans %T Projective representations of extra-special p-groups %J Glasgow mathematical journal %D 1978 %P 149-152 %V 19 %N 2 %U http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003542/ %R 10.1017/S0017089500003542 %F 10_1017_S0017089500003542