@article{DAN_1988_300_1_a4,
     author = {D. A. Derevnin and A. D. Mednykh},
     title = {Geometric properties of discrete groups acting with fixed points in a {Lobachevskii} space},
     journal = {Doklady Akademii Nauk},
     pages = {27--30},
     publisher = {mathdoc},
     volume = {300},
     number = {1},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_300_1_a4/}
}