@article{AL_1973_12_4_a1,
     author = {A. P. Zamyatin},
     title = {Prevarieties of semigroups whose elementary theory is decidable},
     journal = {Algebra i logika},
     pages = {417--432},
     publisher = {mathdoc},
     volume = {12},
     number = {4},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1973_12_4_a1/}
}