@article{DAN_1975_225_5_a8,
     author = {V. I. Sobolev and V. I. Shcherbin},
     title = {On the differentiation of mappings of $K$-spaces},
     journal = {Doklady Akademii Nauk},
     pages = {1020--1022},
     publisher = {mathdoc},
     volume = {225},
     number = {5},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1975_225_5_a8/}
}