@article{AL_1979_18_4_a8,
     author = {V. I. Tumanov},
     title = {Lattices of equational theories of models},
     journal = {Algebra i logika},
     pages = {488--504},
     publisher = {mathdoc},
     volume = {18},
     number = {4},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1979_18_4_a8/}
}