@article{SF_1981__23_134524,
     author = {G.T. Clarke},
     title = {Semigroup varieties of inflations of unions of groups.},
     journal = {Semigroup forum},
     pages = {311--320},
     publisher = {mathdoc},
     volume = {23},
     year = {1981},
     zbl = {0486.20033},
     url = {http://geodesic.mathdoc.fr/item/SF_1981__23_134524/}
}