TY  - JOUR
AU  - P. A. Kuchment
TI  - Periodic perturbations that preserve the law of dispersion of a differential operator
JO  - Differencialʹnye uravneniâ
PY  - 1986
SP  - 1641
EP  - 1642
VL  - 22
IS  - 9
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1986_22_9_a30/
LA  - ru
ID  - DE_1986_22_9_a30
ER  -