@article{HagemannUngelenkWiechert1990,
  author    = {Hagemann, Hans-J{\"u}rgen and Ungelenk, J. and Wiechert, D. U.},
  title     = {Optical time domain reflectometry (OTDR) of diameter modulations in single-mode fibers. Hagemann, H. J.; Ungelenk, J.; Wiechert, D. U.},
  series = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 8 (1990), H. 11},
  journal   = {Journal of Lightwave Technology (J-LT) / Institute of Electrical and Electronics Engineers (IEEE). 8 (1990), H. 11},
  isbn      = {0733-8724},
  pages     = {1641 -- 1645},
  year      = {1990},
  language  = {en}
}
@article{HagemannGeittner1990,
  author    = {Hagemann, Hans-J{\"u}rgen and Geittner, P.},
  title     = {PCVD hybrid technology for single mode fibres. Hagemann, H. J.; Geittner, P.},
  series = {Proceedings : papers presented at: the 8th Annual European Fibre Optic Communications and Local Area Networks Exposition},
  journal   = {Proceedings : papers presented at: the 8th Annual European Fibre Optic Communications and Local Area Networks Exposition},
  pages     = {67 -- 72},
  year      = {1990},
  language  = {en}
}
@article{BullerschenLeonard1990,
  author    = {Bullerschen, Klaus-Gerd and L{\´e}onard, G.},
  title     = {Hochtemperaturtechnik},
  series = {Chemie Ingenieur Technik. 62 (1990), H. 3},
  journal   = {Chemie Ingenieur Technik. 62 (1990), H. 3},
  isbn      = {0009-286X},
  pages     = {252 -- 256},
  year      = {1990},
  language  = {de}
}
@article{Bullerschen1990,
  author    = {Bullerschen, Klaus-Gerd},
  title     = {Rechenmodelle zur Stromverdr{\"a}ngung in ein- und mehrphasigen elektrischen Leitungen komplexer Geometrie},
  series = {Elektrow{\"a}rme International, Edition B (Industrielle Elektrow{\"a}rme). 48 (1990), H. 4},
  journal   = {Elektrow{\"a}rme International, Edition B (Industrielle Elektrow{\"a}rme). 48 (1990), H. 4},
  isbn      = {0340-3521},
  pages     = {199 -- 210},
  year      = {1990},
  language  = {de}
}
@book{Ley1990,
  author    = {Ley, Wilfried},
  title     = {Seilgefesselte Raumflugk{\"o}rper, -Tethertechnik- : Gemeinschaftsveranstaltung der FH Aachen und der DGLR ... / 3. Raumfahrt-Kolloquium an der Fachhochschule Aachen, 13. Dezember 1990. [Wiss. Programmleitung: W. Ley, W. Hallmann]},
  publisher = {DGLR},
  address   = {Bonn},
  isbn      = {3-922010-59-8},
  pages     = {Getr. Z{\"a}hl. : graph. Darst.},
  year      = {1990},
  language  = {de}
}
@book{Harder1990,
  author    = {Harder, J{\"o}rn},
  title     = {Zur Messung von Werkstoffparametern im Torsionsschwingversuch},
  address   = {Braunschweig},
  pages     = {90 S.},
  year      = {1990},
  language  = {de}
}
@book{Koehler1990,
  author    = {K{\"o}hler, Bernd},
  title     = {Werkstofftechnologie der Luft- und Raumfahrt. Teil 3: HT-Superlegierungen},
  publisher = {Mainz},
  address   = {Aachen},
  isbn      = {3-89653-863-2},
  pages     = {191 S. : graph. Darst.},
  year      = {1990},
  language  = {de}
}
@book{Koehler1990,
  author    = {K{\"o}hler, Bernd},
  title     = {Werkstofftechnologie der Luft- und Raumfahrt. Teil 4 : Sonderwerkstoffe. -2. Aufl.},
  publisher = {Mainz},
  address   = {Aachen},
  isbn      = {3-89653-864-6},
  pages     = {148 S. : graph. Darst.},
  year      = {1990},
  language  = {de}
}
@book{Koehler1990,
  author    = {K{\"o}hler, Bernd},
  title     = {Werkstofftechnologie der Luft- und Raumfahrt. Teil 1 : Grundlagen. -2. Aufl.},
  publisher = {Mainz},
  address   = {Aachen},
  isbn      = {3-89653-861-6},
  pages     = {183 S. : graph. Darst.},
  year      = {1990},
  language  = {de}
}
@book{Koehler1990,
  author    = {K{\"o}hler, Bernd},
  title     = {Werkstofftechnologie der Luft- und Raumfahrt. Teil 2 : Leichtmetalle und St{\"a}hle},
  publisher = {Mainz},
  address   = {Aachen},
  isbn      = {3-89653-862-4},
  pages     = {194 S. : graph. Darst.},
  year      = {1990},
  language  = {de}
}