@article{IM_1975__29_142335,
     author = {N. Peczynski and G. Rosenberger},
     title = {\"Uber {Erzeugende} ebener diskontinuierlicher {Gruppen.}},
     journal = {Inventiones mathematicae},
     pages = {161--180},
     publisher = {mathdoc},
     volume = {29},
     year = {1975},
     zbl = {0311.20031},
     url = {http://geodesic.mathdoc.fr/item/IM_1975__29_142335/}
}