TY  - JOUR
AU  - A. A. Borisenko
TI  - Complete $l$-dimensional surfaces of nonpositive extrinsic curvature in a~Riemannian space
JO  - Sbornik. Mathematics
PY  - 1977
SP  - 485
EP  - 499
VL  - 33
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1977_33_4_a2/
LA  - en
ID  - SM_1977_33_4_a2
ER  -