@article{DE_1972_8_2_a12,
     author = {A. B. Antonevich},
     title = {The index and the normal solvability of a general elliptic boundary value problem with a finite group of shifts on the boundary},
     journal = {Differencialʹnye uravneni\^a},
     pages = {309--317},
     publisher = {mathdoc},
     volume = {8},
     number = {2},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_2_a12/}
}