TY  - JOUR
AU  - A. E. Evzhanov
TI  - A lower bound for the sum of squares of fundamental functions of a second-order selfadjoint elliptic operator
JO  - Differencialʹnye uravneniâ
PY  - 1987
SP  - 62
EP  - 72
VL  - 23
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1987_23_1_a6/
LA  - ru
ID  - DE_1987_23_1_a6
ER  -