@article{SF_1994__49_2_135346,
     author = {S. Zhang and C.A. Vachuska},
     title = {Varieties of completely regular semigroups generated by {Mal'cev} products.},
     journal = {Semigroup forum},
     pages = {175--194},
     publisher = {mathdoc},
     volume = {49},
     number = {2},
     year = {1994},
     zbl = {0808.20050},
     url = {http://geodesic.mathdoc.fr/item/SF_1994__49_2_135346/}
}