@book{Wahle1999,
  author    = {Wahle, Michael},
  title     = {Angewandte Strukturanalyse. - (Dynamik)},
  publisher = {Mainz},
  address   = {Aachen},
  isbn      = {3-89653-567-6},
  pages     = {120, A41 S. : Ill., graph. Darst.},
  year      = {1999},
  language  = {de}
}
@book{Wahle1995,
  author    = {Wahle, Michael},
  title     = {Grundlagen der Maschinen- und Strukturdynamik. - (H{\"o}here Technische Mechanik ; 2)},
  edition   = {1. Aufl.},
  publisher = {Mainz},
  address   = {Aachen},
  isbn      = {3-930911-61-2},
  pages     = {216 S. : graph. Darst.},
  year      = {1995},
  language  = {de}
}