TY  - JOUR
AU  - V. P. Nozdracheva
TI  - A priori estimation of the length of a closed trajectory on a plane
JO  - Differencialʹnye uravneniâ
PY  - 1989
SP  - 229
EP  - 233
VL  - 25
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1989_25_2_a7/
LA  - ru
ID  - DE_1989_25_2_a7
ER  -