@article{SF_1985__32_134764,
     author = {G. Hansoul and J. Varlet},
     title = {Perfect semilattices.},
     journal = {Semigroup forum},
     pages = {23--30},
     year = {1985},
     volume = {32},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SF_1985__32_134764/}
}