TY  - JOUR
AU  - Yu. A. Semenov
TI  - On the spectral theory of second-order elliptic differential operators
JO  - Sbornik. Mathematics
PY  - 1987
SP  - 221
EP  - 247
VL  - 56
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1987_56_1_a13/
LA  - en
ID  - SM_1987_56_1_a13
ER  -