TY  - JOUR
AU  - V. M. Babich
AU  - B. M. Levitan
TI  - The focussing problem and the asymptotic behavior of the spectral function of the Laplace--Beltrami operator
JO  - Doklady Akademii Nauk
PY  - 1976
SP  - 1017
EP  - 1020
VL  - 230
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1976_230_5_a0/
LA  - ru
ID  - DAN_1976_230_5_a0
ER  -