@article{DAN_1972_204_1_a7,
     author = {P. A. Kuchment},
     title = {On the index of {Fredholm} operators in a family of {Banach} spaces},
     journal = {Doklady Akademii Nauk},
     pages = {31--33},
     publisher = {mathdoc},
     volume = {204},
     number = {1},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1972_204_1_a7/}
}