TY  - JOUR
AU  - Ibrahim, Sobhy El-sayed
TI  - The spectra of general differential operators in the direct sum spaces
JO  - Czechoslovak Mathematical Journal
PY  - 2004
SP  - 9
EP  - 29
VL  - 54
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMJ_2004__54_1_a1/
LA  - en
ID  - CMJ_2004__54_1_a1
ER  -