Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{SF_1978__16_134271, author = {C. Wells}, title = {Extension theories for monoids.}, journal = {Semigroup forum}, pages = {13--36}, publisher = {mathdoc}, volume = {16}, year = {1978}, zbl = {0394.18007}, url = {http://geodesic.mathdoc.fr/item/SF_1978__16_134271/} }
C. Wells. Extension theories for monoids.. Semigroup forum, Tome 16 (1978), pp. 13-36. http://geodesic.mathdoc.fr/item/SF_1978__16_134271/