TY  - JOUR
AU  - D. V. Tunitsky
TI  - Regular isometric immersion in the~large of two-dimensional metrics of nonpositive curvature
JO  - Sbornik. Mathematics
PY  - 1993
SP  - 317
EP  - 329
VL  - 76
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1993_76_2_a4/
LA  - en
ID  - SM_1993_76_2_a4
ER  -