@article{MZM_1971_9_2_a6,
     author = {V. S. Kozyakin},
     title = {A functional equation},
     journal = {Matemati\v{c}eskie zametki},
     pages = {161--170},
     publisher = {mathdoc},
     volume = {9},
     number = {2},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1971_9_2_a6/}
}