@article{AL_1991_30_4_a2,
     author = {M. G. Peretyat'kin},
     title = {Semantically universal classes of models},
     journal = {Algebra i logika},
     pages = {414--431},
     publisher = {mathdoc},
     volume = {30},
     number = {4},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1991_30_4_a2/}
}