@article{VMUMM_2013_6_a10,
     author = {D. K. Podol'ko},
     title = {Classes of functions closed with respect to a special superposition operation},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {54--57},
     publisher = {mathdoc},
     number = {6},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2013_6_a10/}
}