@article{DAN_1962_145_3_a16,
     author = {\`E. R. Rozendorn},
     title = {Properties of asymptotic lines on surfaces with slowly varying negative curvature},
     journal = {Doklady Akademii Nauk},
     pages = {538--540},
     year = {1962},
     volume = {145},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1962_145_3_a16/}
}