@article{DAN_1961_140_6_a38,
     author = {K. K. Billevich and T. K. Shulikina},
     title = {{\CYRP}{\cyri}{\cyrs}{\cyrsftsn}{\cyrm}{\cyro} {\cyrv}~{\cyrr}{\cyre}{\cyrd}{\cyra}{\cyrk}{\cyrc}{\cyri}{\cyryu}},
     journal = {Doklady Akademii Nauk},
     pages = {1235--1236},
     publisher = {mathdoc},
     volume = {140},
     number = {6},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_140_6_a38/}
}