@article{SF_1982__24_134559,
     author = {G. Lallement},
     title = {Semigroups and combinatorial applications - {Perrot,} {J.F.}},
     journal = {Semigroup forum},
     pages = {385--390},
     publisher = {mathdoc},
     volume = {24},
     year = {1982},
     url = {http://geodesic.mathdoc.fr/item/SF_1982__24_134559/}
}