@article{UFA_2016_8_3_a10,
     author = {A. Yu. Savin and B. Yu. Sternin},
     title = {Homotopy classification of elliptic problems associated with discrete group actions on manifolds with boundary},
     journal = {Ufa mathematical journal},
     pages = {122--129},
     publisher = {mathdoc},
     volume = {8},
     number = {3},
     year = {2016},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/UFA_2016_8_3_a10/}
}