@article{SF_1991__43_3_135111, author = {P.A. Grillet}, title = {Commutative semigroup cohomology.}, journal = {Semigroup forum}, pages = {247--252}, publisher = {mathdoc}, volume = {43}, number = {3}, year = {1991}, zbl = {0742.20067}, url = {http://geodesic.mathdoc.fr/item/SF_1991__43_3_135111/} }