@book{BlomeHoellPriester1988,
  author    = {Blome, Hans-Joachim and Hoell, Josef and Priester, Wolfgang},
  title     = {Neue Aspekte der Kosmologie},
  publisher = {Inst. f{\"u}r Astrophysik},
  address   = {Bonn},
  pages     = {100 S : graph. Darst.},
  year      = {1988},
  language  = {de}
}
@book{Ley1988,
  author    = {Ley, Wilfried},
  title     = {Handbuch der Raumfahrttechnik : Grundlagen - Nutzung, Raumfahrtsysteme - Produktsicherung u. Produktmanagement / Willi Hallmann; Wilfried Ley},
  publisher = {Hanser},
  address   = {M{\"u}nchen [u.a.]},
  isbn      = {3446151303},
  pages     = {XVIII, 792 S : Ill., graph. Darst.},
  year      = {1988},
  language  = {de}
}