%0 Journal Article
%A Cegarra, A. M.
%A Garćia-Calcines, J. M.
%A Ortega, J. A.
%T On Graded Categorical Groups and Equivariant Group Extensions
%J Canadian journal of mathematics
%D 2002
%P 970-997
%V 54
%N 5
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-2002-036-1/
%R 10.4153/CJM-2002-036-1
%F 10_4153_CJM_2002_036_1