%0 Journal Article
%A Macdonald, I. D.
%T Groups of breadth four have class five
%J Glasgow mathematical journal
%D 1978
%P 141-148
%V 19
%N 2
%U http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003530/
%R 10.1017/S0017089500003530
%F 10_1017_S0017089500003530