@article{VSGU_2013_6_a6,
     author = {N. L. Poliakov and M. V. Shamolin},
     title = {On symmetric closed class of function preserving every unary predicate},
     journal = {Vestnik Samarskogo universiteta. Estestvennonau\v{c}na\^a seri\^a},
     pages = {61--73},
     publisher = {mathdoc},
     number = {6},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VSGU_2013_6_a6/}
}