@article{VMUMM_2015_2_a4,
     author = {D. K. Podol'ko},
     title = {A family of classes of functions closed with respect to a strengthened superposition operation},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {27--31},
     publisher = {mathdoc},
     number = {2},
     year = {2015},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2015_2_a4/}
}