TY  - JOUR
AU  - R. V. Akopyan
TI  - Perturbation theory for $J$-positive operators
JO  - Funkcionalʹnyj analiz i ego priloženiâ
PY  - 1975
SP  - 61
EP  - 62
VL  - 9
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/FAA_1975_9_2_a8/
LA  - ru
ID  - FAA_1975_9_2_a8
ER  -