@article{MZM_1969_6_4_a1,
     author = {S. I. Fedishchenko},
     title = {Infinitely small transformations preserving the curvature of {a~Riemannian} space},
     journal = {Matemati\v{c}eskie zametki},
     pages = {371--380},
     year = {1969},
     volume = {6},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1969_6_4_a1/}
}