TY  - JOUR
AU  - D. V. Treschev
TI  - On the problem of the periodic trajectories of the Birkhoff billiard
JO  - Vestnik Moskovskogo universiteta. Matematika, mehanika
PY  - 1987
SP  - 72
EP  - 75
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/VMUMM_1987_5_a15/
LA  - ru
ID  - VMUMM_1987_5_a15
ER  -