@article{BrungsGraeter1996,
  author    = {Brungs, Hans and Gr{\"a}ter, Joachim},
  title     = {Orders of Higher Rank in Semisimple Artinian Rings},
  year      = {1996},
  language  = {en}
}
@article{Graeter1996,
  author    = {Gr{\"a}ter, Joachim},
  title     = {Algebraic elements in division rings},
  year      = {1996},
  language  = {en}
}
@article{Graeter1996,
  author    = {Gr{\"a}ter, Joachim},
  title     = {Extending valuation rings via ultrafilters},
  year      = {1996},
  language  = {en}
}