TY  - JOUR
AU  - M. G. Krein
AU  - G. K. Langer
TI  - On the theory of quadratic pencils of self-adjoint operators
JO  - Doklady Akademii Nauk
PY  - 1964
SP  - 1258
EP  - 1261
VL  - 154
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1964_154_6_a3/
LA  - ru
ID  - DAN_1964_154_6_a3
ER  -