@article{AL_2010_49_6_a4,
     author = {E. A. Palyutin},
     title = {Categorical {Horn} classes.~2},
     journal = {Algebra i logika},
     pages = {782--802},
     publisher = {mathdoc},
     volume = {49},
     number = {6},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2010_49_6_a4/}
}