@article{1077465876,
author = {MacKenzie, Robert E.},
title = {Commutative semigroups},
journal = {Duke Math. J.},
volume = {21},
number = {1},
year = {1954},
pages = { 471-477},
language = {en},
url = {http://dml.mathdoc.fr/item/1077465876}
}
MacKenzie, Robert E. Commutative semigroups. Duke Math. J., Tome 21 (1954) no. 1, pp. 471-477. http://gdmltest.u-ga.fr/item/1077465876/