@inproceedings{FJ65,
  author =       "K. Ferber and H. J\accent127urgensen",
  title =        "{A Programme for Drawing a Lattice}",
  booktitle =    "Computational Problems in Abstract Algebra",
  editor =       "J. Leech",
  year =         1970,
  pages =        "83--86",                                                    
}                                                                               
                                                                                
@inproceedings{HR91,
  author =       "Derek F. Holt and Sarah Rees",
  title =        "{A Graphics System for Displaying Finite Quotients of Finitely Presented Groups}",
  booktitle =    "Groups and Computation",
  editor =       "L. Finkelstein and W. M. Kantor",
  year =         "1991",
  notes =        "DIMACS",
  pages =        "113--126"
}

@mastersthesis{SK95,
  author       = "Susanne Keitemeier",
  title        = "{Graphische Darstellung von Untergruppendiagrammen im Computeralge\-bra\-pro\-gramm {\GAP}}",
  type         = "Diplomarbeit",
  year         = "1995",
  school       = RWTHLDfM,
  address      = RWTH-A,
}                                                                               
@article{Cav86,
  author       = "Alberto Cavicchioli",
  title        = "{A countable class of non-homeomorphic homology spheres with Heegaard genus two}",
  year         = "1986",
  journal      = "Geom. Dedicata",
  volume       = 20,
  pages        = "345--348"
}