TY  - JOUR
AU  - M. M. Malamud
TI  - Necessary conditions for the existence of a transformation operator for higher-order equations
JO  - Funkcionalʹnyj analiz i ego priloženiâ
PY  - 1982
SP  - 74
EP  - 75
VL  - 16
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/FAA_1982_16_3_a16/
LA  - ru
ID  - FAA_1982_16_3_a16
ER  -