TY  - JOUR
AU  - Yu. G. Safarov
TI  - Exact asymptotics of the spectrum of a~boundary value problem, and periodic billiards
JO  - Izvestiya. Mathematics 
PY  - 1989
SP  - 553
EP  - 573
VL  - 33
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_1989_33_3_a4/
LA  - en
ID  - IM2_1989_33_3_a4
ER  -