@article{DAN_1963_149_3_a14,
     author = {A. L. Shmel'kin},
     title = {The semigroup of group varieties},
     journal = {Doklady Akademii Nauk},
     pages = {543--545},
     publisher = {mathdoc},
     volume = {149},
     number = {3},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1963_149_3_a14/}
}