Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{SF_1980__21_134435, author = {C.C. Edmunds}, title = {Varieties generated by semigroups of order four.}, journal = {Semigroup forum}, pages = {67--82}, publisher = {mathdoc}, volume = {21}, year = {1980}, zbl = {0449.20060}, url = {http://geodesic.mathdoc.fr/item/SF_1980__21_134435/} }
C.C. Edmunds. Varieties generated by semigroups of order four.. Semigroup forum, Tome 21 (1980), pp. 67-82. http://geodesic.mathdoc.fr/item/SF_1980__21_134435/