@article{RM_1966_21_5_a1,
     author = {\`E. R. Rozendorn},
     title = {Weakly irregular surfaces of negative curvature},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {57--112},
     publisher = {mathdoc},
     volume = {21},
     number = {5},
     year = {1966},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1966_21_5_a1/}
}