@article{SF_1984__30_134706,
     author = {N.R. Reilly and J. Almeida},
     title = {Generalized varieties of commutative and nilpotent semigroups.},
     journal = {Semigroup forum},
     pages = {77--98},
     publisher = {mathdoc},
     volume = {30},
     year = {1984},
     zbl = {0528.20042},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__30_134706/}
}