@article{WittmannKehrWillnecker2000,
  author    = {Wittmann, Klaus and Kehr, J. and Willnecker, R.},
  title     = {Decentralized Payload Operations Concept for Columbus},
  year      = {2000},
  language  = {en}
}
@book{LeyWittmannHallmann2009,
  author    = {Ley, Wilfried and Wittmann, Klaus and Hallmann, Willi},
  title     = {Handbook of space technology},
  publisher = {Wiley},
  address   = {Chichester},
  isbn      = {978-0-470-69739-9},
  pages     = {XIII, 882 S. : Ill., graph. Darst.},
  year      = {2009},
  language  = {en}
}
@book{WittmannLeyHallmann2008,
  author    = {Wittmann, Klaus and Ley, Wilfried [Hrsg.] and Hallmann, Willi [Hrsg.]},
  title     = {Handbuch der Raumfahrttechnik : mit 128 Tabellen / Wilfried Ley; Klaus Wittmann; Willi Hallmann (Hrsg.) 3., v{\"o}llig neu bearb. und erw. Aufl.},
  publisher = {Hanser},
  address   = {M{\"u}nchen},
  isbn      = {978-3-446-41185-2},
  pages     = {814 S. : Ill., graph. Darst.},
  year      = {2008},
  language  = {de}
}
@article{WittmannKellWinkleretal.1998,
  author    = {Wittmann, Klaus and Kell, G. and Winkler, F. and G{\"u}nther, M. (u.a.)},
  title     = {High resolution temperature measurement technique for materials sciences experiments in space},
  series = {Acta Astronautica. 43 (1998), H. 7-8},
  journal   = {Acta Astronautica. 43 (1998), H. 7-8},
  isbn      = {0094-5765},
  pages     = {385 -- 395},
  year      = {1998},
  language  = {en}
}
@article{WittmannUlamecRichter1999,
  author    = {Wittmann, Klaus and Ulamec, S and Richter, L},
  title     = {Lander Systems for Planetary Missions},
  series = {Laboratory astrophysics and space research / ed. by P. Ehrenfreund},
  journal   = {Laboratory astrophysics and space research / ed. by P. Ehrenfreund},
  publisher = {Kluwer},
  address   = {Dordrecht [u.a.]},
  isbn      = {0-7923-5338-2},
  pages     = {597 -- 621},
  year      = {1999},
  language  = {en}
}
@article{WittmannSchmidtFeuerbacher1988,
  author    = {Wittmann, Klaus and Schmidt, H. P. and Feuerbacher, B.},
  title     = {Microgravity research and user support in the Space Station era: The Microgravity User Support Centre},
  series = {Acta Astronautica. 17 (1988), H. 11-12},
  journal   = {Acta Astronautica. 17 (1988), H. 11-12},
  isbn      = {0094-5765},
  pages     = {1161 -- 1168},
  year      = {1988},
  language  = {en}
}
@article{Wittmann2000,
  author    = {Wittmann, Klaus},
  title     = {Overview of Space Operations at DLR},
  year      = {2000},
  language  = {en}
}
@article{WittmannFeuerbacherUlamecetal.1999,
  author    = {Wittmann, Klaus and Feuerbacher, B. and Ulamec, S. and Rosenbauer, H. (u.a.)},
  title     = {Rosetta Lander - In Situ Characterisation of a Comet Nucleus},
  series = {Acta Astronautica. 45 (1999), H. 4-9},
  journal   = {Acta Astronautica. 45 (1999), H. 4-9},
  isbn      = {0094-5765},
  pages     = {389 -- 395},
  year      = {1999},
  language  = {en}
}
@article{WittmannUlamecFeuerbacheretal.1997,
  author    = {Wittmann, Klaus and Ulamec, S. and Feuerbacher, B. and Rosenbauer, H. (u.a.)},
  title     = {Rosetta Lander - In Situ Investigation of a Cometary Nucleus},
  series = {Lunar and Planetary Science. 28 (1997)},
  journal   = {Lunar and Planetary Science. 28 (1997)},
  isbn      = {0270-9511},
  pages     = {1461 -- 1462},
  year      = {1997},
  language  = {en}
}
@article{WittmannBewersdorffGoerleretal.1993,
  author    = {Wittmann, Klaus and Bewersdorff, A. and G{\"o}rler, G.P. and Otto, G.},
  title     = {Solidification of silver-germanium alloys in an amorphous matrix aboard the space station Mir},
  series = {Acta Astronautica. 29 (1993), H. 7},
  journal   = {Acta Astronautica. 29 (1993), H. 7},
  isbn      = {0094-5765},
  pages     = {547 -- 552},
  year      = {1993},
  language  = {en}
}