@article{10_1017_S0017089500000987,
     author = {McAlister, D. B. and O'Carroll, L.},
     title = {Finitely generated commutative semigroups},
     journal = {Glasgow mathematical journal},
     pages = {134--151},
     year = {1970},
     volume = {11},
     number = {2},
     doi = {10.1017/S0017089500000987},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500000987/}
}