TY  - JOUR
AU  - S. Ya. Yakubov
TI  - Multiple completeness in the sense of M.\,V.~Keldysh of root functions of elliptic boundary value problems with a~polynomial spectral parameter
JO  - Izvestiya. Mathematics 
PY  - 1987
SP  - 413
EP  - 420
VL  - 28
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_1987_28_2_a7/
LA  - en
ID  - IM2_1987_28_2_a7
ER  -