TY  - JOUR
AU  - B. R. Lavruk
TI  - The index of a boundary problem operator for an elliptical system of second order linear differential equations, 

JO  - Doklady Akademii Nauk
PY  - 1958
SP  - 970
EP  - 972
VL  - 121
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1958_121_6_a3/
LA  - ru
ID  - DAN_1958_121_6_a3
ER  -