TY  - JOUR
AU  - S. R. Umarov
AU  - È. M. Saidamatov
TI  - On conditions for the discreteness of the spectrum for a general pseudo-differential operator
JO  - Differencialʹnye uravneniâ
PY  - 1997
SP  - 133
EP  - 135
VL  - 33
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1997_33_1_a19/
LA  - ru
ID  - DE_1997_33_1_a19
ER  -