TY  - JOUR
AU  - N. V. Efimov
TI  - The validity of Hilbert's theorem on surfaces of constant negative curvature
JO  - Doklady Akademii Nauk
PY  - 1961
SP  - 1283
EP  - 1286
VL  - 136
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1961_136_6_a5/
LA  - ru
ID  - DAN_1961_136_6_a5
ER  -