@phdthesis{Sprengel1992,
  author    = {Sprengel, Jens-Uwe},
  title     = {Analyse der Transfermatrizen geschichteter anisotroper Medien},
  pages     = {92 Bl., 3 S.},
  year      = {1992},
  language  = {de}
}
@article{QuaisserSprengel1997,
  author    = {Quaisser, Erhard and Sprengel, Jens-Uwe},
  title     = {Polyominos und Puzzles},
  year      = {1997},
  language  = {de}
}