@article{460441,
      author = {Fenchel, W. and Nielsen, Jakob, and Schmidt, Asmus L.},
      url = {http://library.usi.edu/record/460441},
      title = {Discontinuous groups of isometries in the hyperbolic plane  [electronic resource] /},
      publisher = {Walter de Gruyter,},
      recid = {460441},
      pages = {xxi, 364 p. :},
      address = {Berlin ;},
      year = {2003},
}