@article{SF_1982__25_134561,
     author = {G. Poll\'ak},
     title = {On two classes of hereditarily finitely based semigroup identities.},
     journal = {Semigroup forum},
     pages = {9--34},
     publisher = {mathdoc},
     volume = {25},
     year = {1982},
     zbl = {0496.20042},
     url = {http://geodesic.mathdoc.fr/item/SF_1982__25_134561/}
}