TY  - JOUR
AU  - Yu. K. Lando
TI  - The $F$-index and $F$-normal solvability of integro-differential operators
JO  - Differencialʹnye uravneniâ
PY  - 1969
SP  - 546
EP  - 555
VL  - 5
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1969_5_3_a14/
LA  - ru
ID  - DE_1969_5_3_a14
ER  -