@article{MP_2020_3_25_a1,
     author = {D. G. Efimov and M. J. Pratussevitch},
     title = {{\CYRK}{\cyrr}{\cyra}{\cyrt}{\cyrk}{\cyra}{\cyrya} {\cyri}{\cyrs}{\cyrt}{\cyro}{\cyrr}{\cyri}{\cyrya} {{\CYRA}{\cyrn}{\cyrn}{\cyre}{\cyrn}{\cyrsh}{\cyru}{\cyrl}{\cyre}} {\textemdash} {{\CYRF}{\CYRM}{\CYRL}} 239},
     journal = {Matematicheskoe Prosveshchenie},
     pages = {7--17},
     year = {2020},
     volume = {Ser. 3, 25},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MP_2020_3_25_a1/}
}