@article{DAN_1966_170_5_a5,
     author = {A. P. Kopylov},
     title = {Homeomorphic mappings in the three-dimensional {Euclidean} space preserving angles of rays},
     journal = {Doklady Akademii Nauk},
     pages = {1016--1017},
     publisher = {mathdoc},
     volume = {170},
     number = {5},
     year = {1966},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1966_170_5_a5/}
}