@article{RM_1973_28_2_a17,
     author = {O. V. Schwarzman},
     title = {Discrete groups with simply connected nonsingular quotient space},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {28},
     number = {2},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1973_28_2_a17/}
}