@article{DAN_1980_250_5_a7,
     author = {I. G. Nikolaev},
     title = {Parallel translation and smoothness of the metric of spaces of bounded curvature},
     journal = {Doklady Akademii Nauk},
     pages = {1056--1058},
     publisher = {mathdoc},
     volume = {250},
     number = {5},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_250_5_a7/}
}