@article{MZ_1972__128_171803,
     author = {Gerhard Rosenberger and Norman Purzitsky},
     title = {Two {Generator} {Fuchsian} {Groups} of {Genus} {One.}},
     journal = {Mathematische Zeitschrift},
     pages = {245--252},
     publisher = {mathdoc},
     volume = {128},
     year = {1972},
     zbl = {0232.20105},
     url = {http://geodesic.mathdoc.fr/item/MZ_1972__128_171803/}
}