%0 Journal Article
%A D. Cowan
%T An associative operator  on the lattice of varieties of inverse semigroups.
%J Semigroup forum
%D 1992
%P 288-301
%V 45
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1992__45_3_135193/
%F SF_1992__45_3_135193