@article{MS_1957__85_2_a0,
     author = {{\CYRE}.{\CYRM}. {\CYRL}{\cyra}{\cyrn}{\cyrd}{\cyri}{\cyrs} and {\CYRI}.{\CYRG}. {\CYRP}{\cyre}{\cyrt}{\cyrr}{\cyro}{\cyrv}{\cyrs}{\cyrk}{\cyri}{\cyrishrt}},
     title = {{\CYRO} {\cyrch}{\cyri}{\cyrs}{\cyrl}{\cyre} {\cyrp}{\cyrr}{\cyre}{\cyrd}{\cyre}{\cyrl}{\cyrsftsn}{\cyrn}{\cyrery}{\cyrh} {\cyrc}{\cyri}{\cyrk}{\cyrl}{\cyro}{\cyrv} {\cyru}{\cyrr}{\cyra}{\cyrv}{\cyrn}{\cyre}{\cyrn}{\cyri}{\cyrya} ${dy {\o}ver dx} = {P(x, y) {\o}ver Q(x, y)}$, {\cyrg}{\cyrd}{\cyre} $P$ {\cyri} $Q$- {\cyrp}{\cyro}{\cyrl}{\cyri}{\cyrn}{\cyro}{\cyrm}{\cyrery}},
     journal = {Matemati\v{c}eskij sbornik},
     pages = {149--168},
     publisher = {mathdoc},
     volume = {85},
     number = {2},
     year = {1957},
     zbl = {0079.30801},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MS_1957__85_2_a0/}
}