@book{BBNWZ78,
  author    = {H. Brown and R. Bülow and J. Neubüser and
               H. Wondratschek and H. Zassenhaus},
  title     = {Crystallographic Groups of Four-Dimensional Space},
  publisher = {John Wiley},
  address   = {New York},
  year      = {1978},
}

@article{EGN97,
  author  = {F. Gähler and B. Eick and W. Nickel},
  title   = {Computing maximal subgroups and {Wyckoff} positions of
             space groups},
  journal = {Acta Cryst. A},
  volume  = {53},
  pages   = {467--474},
  year    = {1997},
}

@book{Hah95,
  editor    = {T. Hahn},
  title     = {International Tables for Crystallography,
               Volume A, Space-group Symmetry},
  edition   = {4th},
  publisher = {Kluwer},
  address   = {Dordrecht},
  year      = {1995},
}

@incollection{Won95,
  author    = {H. Wondratschek},
  title     = {Introduction to space-group symmetry},
  booktitle = {International Tables for Crystallography,
               Volume A, Space-group Symmetry},
  editor    = {T. Hahn},
  edition   = {4th},
  publisher = {Kluwer},
  address   = {Dordrecht},
  pages     = {711--735},
  year      = {1995},
}
