@article{AL_1988_27_3_a4,
     author = {A. G. Pinus},
     title = {Coverings in epimorphism skeletons of varieties of algebras},
     journal = {Algebra i logika},
     pages = {316--326},
     publisher = {mathdoc},
     volume = {27},
     number = {3},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1988_27_3_a4/}
}