@article{10_21136_CMJ_1975_101318,
     author = {Rotkovi\v{c}, G. Ja.},
     title = {{\CYRO} $\sigma$-{\cyrp}{\cyro}{\cyrl}{\cyrn}{\cyrery}{\cyrh} {\cyrr}{\cyre}{\cyrsh}{\cyre}{\cyrt}{\cyro}{\cyrch}{\cyrn}{\cyro} {\cyru}{\cyrp}{\cyro}{\cyrr}{\cyrya}{\cyrd}{\cyro}{\cyrch}{\cyre}{\cyrn}{\cyrn}{\cyrery}{\cyrh} {\cyrg}{\cyrr}{\cyru}{\cyrp}{\cyrp}{\cyra}{\cyrh}},
     journal = {Czechoslovak Mathematical Journal},
     pages = {279--281},
     publisher = {mathdoc},
     volume = {25},
     number = {2},
     year = {1975},
     doi = {10.21136/CMJ.1975.101318},
     mrnumber = {0369206},
     zbl = {0317.06013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1975.101318/}
}