@article{DAN_1981_256_5_a0,
     author = {S. V. Buyalo},
     title = {Stability of the topology of hyperbolic space forms under variation of the curvature},
     journal = {Doklady Akademii Nauk},
     pages = {1033--1036},
     publisher = {mathdoc},
     volume = {256},
     number = {5},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_256_5_a0/}
}