TY  - JOUR
AU  - V. F. Lazutkin
TI  - The existence of caustics for a~billiard problem in a~convex domain
JO  - Izvestiya. Mathematics 
PY  - 1973
SP  - 185
EP  - 214
VL  - 7
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_1973_7_1_a8/
LA  - en
ID  - IM2_1973_7_1_a8
ER  -