TY  - JOUR
AU  - E. G. Sitnikova
TI  - A~three spheres theorem for an elliptic equation of high order
JO  - Sbornik. Mathematics
PY  - 1970
SP  - 189
EP  - 195
VL  - 11
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1970_11_2_a3/
LA  - en
ID  - SM_1970_11_2_a3
ER  -