TY  - JOUR
AU  - V. I. Filippenko
TI  - On the multiplicity of a spectrum of a first-order selfadjoint differential operator
JO  - Differencialʹnye uravneniâ
PY  - 1981
SP  - 1135
EP  - 1138
VL  - 17
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1981_17_6_a19/
LA  - ru
ID  - DE_1981_17_6_a19
ER  -