@article{10_1017_S0017089500001257,
     author = {Berthiaume, Pierre},
     title = {Generalized semigroups of quotients},
     journal = {Glasgow mathematical journal},
     pages = {150--161},
     year = {1971},
     volume = {12},
     number = {2},
     doi = {10.1017/S0017089500001257},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500001257/}
}