@article{GDZPPN001262718, title = {Positivity and cohomology for involutive semigroups.}, journal = {Semigroup forum}, volume = {46}, year = {1993}, pages = {60-80}, zbl = {0818.46067}, url = {http://dml.mathdoc.fr/item/GDZPPN001262718} }
Jorgensen, P.E.T.; Quan, X.C. Positivity and cohomology for involutive semigroups.. Semigroup forum, Tome 46 (1993) pp. 60-80. http://gdmltest.u-ga.fr/item/GDZPPN001262718/