@article{ZNSL_1974_47_a17,
     author = {A. L. Rukhin},
     title = {A~note on the {D'Alembert} functional equation},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {182--183},
     year = {1974},
     volume = {47},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1974_47_a17/}
}