@article{SM_1967_1_2_a4,
     author = {N. I. Nagnibida},
     title = {Isomorphisms of analytic spaces that commute with differentiation},
     journal = {Sbornik. Mathematics},
     pages = {221--231},
     year = {1967},
     volume = {1},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1967_1_2_a4/}
}