@article{MP_2023_3_31_a9, author = {A. Ya. Kanel-Belov and I. V. Mitrofanov}, title = {{\CYRU}{\cyrs}{\cyrl}{\cyro}{\cyrv}{\cyri}{\cyrya} {\cyrz}{\cyra}{\cyrd}{\cyra}{\cyrch}}, journal = {Matematicheskoe Prosveshchenie}, pages = {209--212}, year = {2023}, volume = {Ser. 3, 31}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MP_2023_3_31_a9/} }