TY  - JOUR
AU  - D. A. Popov
TI  - Asymptotic behaviour of the positive spectrum of a~family of~periodic Sturm--Liouville problems 

JO  - Izvestiya. Mathematics 
PY  - 2009
SP  - 579
EP  - 610
VL  - 73
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_2009_73_3_a5/
LA  - en
ID  - IM2_2009_73_3_a5
ER  -