TY  - JOUR
AU  - G. I. Shilova
TI  - The number of periodic solutions of the second kind to the differential equation $\ddot{\varphi}-f_1(\varphi)\dot{\varphi}-f_0(\varphi)=0$
JO  - Differencialʹnye uravneniâ
PY  - 1967
SP  - 1682
EP  - 1691
VL  - 3
IS  - 10
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1967_3_10_a5/
LA  - ru
ID  - DE_1967_3_10_a5
ER  -