@Article{ostertag1993-trh8371644,
  author =          {Ostertag, C. B.},
  author =          {Schad, L. R.},
  author =          {Koch, R.},
  author =          {Maier, R.},
  author =          {Wowra, B.},
  title =           {Titanium Riechert head ring for MR stereotaxy. Technical note.},
  journal =         {Acta Neurochir (Wien)},
  year =            {1993},
  volume =          {121},
  pages =           {82-85},
  number =          {1-2},
  institution =     {Abteilung Stereotaktische Neurochirurgie, Neurochirurgische Universitäts-Klinik, Freiburg, Federal Republic of Germany.}}