@article{SM_1972_17_3_a1,
     author = {S. G. Mamikonyan},
     title = {Varieties of finitely approximable semigroups},
     journal = {Sbornik. Mathematics},
     pages = {349--355},
     publisher = {mathdoc},
     volume = {17},
     number = {3},
     year = {1972},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1972_17_3_a1/}
}