TY  - JOUR
AU  - G. V. Demidenko
AU  - A. V. Dulepova
TI  - On periodic solutions of one second-order differential equation
JO  - Contemporary Mathematics. Fundamental Directions
PY  - 2021
SP  - 535
EP  - 548
VL  - 67
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMFD_2021_67_3_a8/
LA  - ru
ID  - CMFD_2021_67_3_a8
ER  -