%0 Journal Article
%A Osterweil, Leon
%T A Theorem for Enumerating Certain Types of Collections
%J Canadian journal of mathematics
%D 1973
%P 74-82
%V 25
%N 1
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1973-005-8/
%R 10.4153/CJM-1973-005-8
%F 10_4153_CJM_1973_005_8