TY  - JOUR
AU  - V. M. Babich
AU  - B. M. Levitan
TI  - Problem of focusing and the asymptotics of the spectral function of the Laplace--Beltrami operator.~I
JO  - Zapiski Nauchnykh Seminarov POMI
PY  - 1978
SP  - 3
EP  - 19
VL  - 78
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/ZNSL_1978_78_a0/
LA  - ru
ID  - ZNSL_1978_78_a0
ER  -