TY  - JOUR
AU  - V. S. Belonosov
TI  - Instability indices of differential operators
JO  - Sbornik. Mathematics
PY  - 1987
SP  - 507
EP  - 525
VL  - 57
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1987_57_2_a12/
LA  - en
ID  - SM_1987_57_2_a12
ER  -