Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MS_1968__117_1_a3, author = {{\CYRA}.{\CYRYU}. {\CYRL}{\cyre}{\cyrv}{\cyri}{\cyrn}}, title = {{\CYRP}{\cyro}{\cyrv}{\cyre}{\cyrd}{\cyre}{\cyrn}{\cyri}{\cyre} {\cyrr}{\cyre}{\cyrsh}{\cyre}{\cyrn}{\cyri}{\cyrishrt} {\cyru}{\cyrr}{\cyra}{\cyrv}{\cyrn}{\cyre}{\cyrn}{\cyri}{\cyrya} $\ddot{x}+p(t)\dot{x}+q(t)x=0$ {\cyrv} {\cyrn}{\cyre}{\cyrk}{\cyro}{\cyrl}{\cyre}{\cyrb}{\cyra}{\cyrt}{\cyre}{\cyrl}{\cyrsftsn}{\cyrn}{\cyro}{\cyrm} {\cyrs}{\cyrl}{\cyru}{\cyrch}{\cyra}{\cyre}}, journal = {Matemati\v{c}eskij sbornik}, pages = {39--63}, publisher = {mathdoc}, volume = {117}, number = {1}, year = {1968}, zbl = {0165.40802}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MS_1968__117_1_a3/} }
А.Ю. Левин. Поведение решений уравнения $\ddot{x}+p(t)\dot{x}+q(t)x=0$ в неколебательном случае. Matematičeskij sbornik, Tome 117 (1968) no. 1, pp. 39-63. http://geodesic.mathdoc.fr/item/MS_1968__117_1_a3/