@article{MP_2021_3_27_a16, 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 = {233--236}, year = {2021}, volume = {Ser. 3, 27}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MP_2021_3_27_a16/} }