@article{HagemannHennings1981,
  author    = {Hagemann, Hans-J{\"u}rgen and Hennings, D.},
  title     = {Reversible Weight change of acceptor-doped BaTiO3. Hagemann, H. J.; Hennings, D.},
  series = {Journal of the American Ceramic Society. 64 (1981)},
  journal   = {Journal of the American Ceramic Society. 64 (1981)},
  isbn      = {0002-7820},
  pages     = {590 -- 594},
  year      = {1981},
  language  = {en}
}
@article{HagemannHenningsWernicke1984,
  author    = {Hagemann, Hans-J{\"u}rgen and Hennings, D. and Wernicke, R.},
  title     = {Ceramic multilayer capacitors. Hagemann, H. J.; Hennings, D.; Wernicke, R.},
  series = {Philips' technical review / Philips' Gloeilampenfabrieken. Philips' Gloeilampenfabrieken <Eindhoven>. 41 (1984)},
  journal   = {Philips' technical review / Philips' Gloeilampenfabrieken. Philips' Gloeilampenfabrieken <Eindhoven>. 41 (1984)},
  isbn      = {0031-7926},
  pages     = {89 -- 98},
  year      = {1984},
  language  = {en}
}
@article{HagemannHenningsWernicke1984,
  author    = {Hagemann, Hans-J{\"u}rgen and Hennings, D. and Wernicke, R.},
  title     = {Keramische Vielschichtkondensatoren. Hagemann, H. J.; Hennings, D.; Wernicke, R.},
  series = {Sprechsaal : internat. ceramics \& glass magazine. 117 (1984)},
  journal   = {Sprechsaal : internat. ceramics \& glass magazine. 117 (1984)},
  isbn      = {0341-0439},
  pages     = {924 -- 931},
  year      = {1984},
  language  = {de}
}