@article{SM_1967_1_3_a7,
     author = {\`E. B. Vinberg},
     title = {Discrete groups generated by reflections in {Lobachevskii} spaces},
     journal = {Sbornik. Mathematics},
     pages = {429--444},
     publisher = {mathdoc},
     volume = {1},
     number = {3},
     year = {1967},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1967_1_3_a7/}
}