@article{AL_1964_3_2_a1,
     author = {A. V. Gladkii},
     title = {The algorithmic character of invariant properties of},
     journal = {Algebra i logika},
     pages = {17--31},
     publisher = {mathdoc},
     volume = {3},
     number = {2},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1964_3_2_a1/}
}