@article{BAG_1986__21_138325,
     author = {B. Klotzek},
     title = {Discontinuous groups in some metric and nonmetric spaces},
     journal = {Beitr\"age zur Algebra und Geometrie},
     pages = {57--66},
     year = {1986},
     volume = {21},
     zbl = {0592.51021},
     url = {http://geodesic.mathdoc.fr/item/BAG_1986__21_138325/}
}