@article{MP_1957_2_1_a11,
     author = {N. M. Beskin},
     title = {{\CYRT}{\cyre}{\cyro}{\cyrr}{\cyre}{\cyrm}{\cyrery} {{\CYRCH}{\cyre}{\cyrv}{\cyrery}} {\cyri} {{\CYRM}{\cyre}{\cyrn}{\cyre}{\cyrl}{\cyra}{\cyrya}} {\cyrv}~$n$-{\cyrm}{\cyre}{\cyrr}{\cyrn}{\cyro}{\cyrm} {\cyrp}{\cyrr}{\cyro}{\cyrs}{\cyrt}{\cyrr}{\cyra}{\cyrn}{\cyrs}{\cyrt}{\cyrv}{\cyre}},
     journal = {Matematicheskoe Prosveshchenie},
     pages = {119--127},
     year = {1957},
     volume = {Ser. 2, 1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MP_1957_2_1_a11/}
}