@article{INTF_1989_48_a1,
     author = {\`E. R. Rozendorn},
     title = {Surfaces of negative curvature},
     journal = {Itogi Nauki i Tekhniki. Seriya Sovremennye Problemy Matematiki. Fundamental'nye Napravleniya },
     pages = {98--195},
     publisher = {mathdoc},
     volume = {48},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTF_1989_48_a1/}
}