@article{BUMI_2006_8_9B_1_a6,
     author = {Cegarra, Antonio M. and Petrich, Mario},
     title = {Commutative cancellative semigroups and rational vector spaces},
     journal = {Bollettino della Unione matematica italiana},
     pages = {133--144},
     publisher = {mathdoc},
     volume = {Ser. 8, 9B},
     number = {1},
     year = {2006},
     zbl = {1147.20317},
     mrnumber = {2204904},
     language = {it},
     url = {https://geodesic-test.mathdoc.fr/item/BUMI_2006_8_9B_1_a6/}
}