TY  - JOUR
AU  - V. A. Il'in
TI  - A lower bound of the sum of the squares of the fundamental functions, and of the number of the fundamental values, for an arbitrary $FSF$ of Laplace's operator
JO  - Differencialʹnye uravneniâ
PY  - 1970
SP  - 7
EP  - 16
VL  - 6
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1970_6_1_a1/
LA  - ru
ID  - DE_1970_6_1_a1
ER  -