@article{PietschKurbel1989,
  author    = {Pietsch, Wolfram and Kurbel, Karl},
  title     = {Expertensystem-Projekte. Entwicklungsmethodik, Organisation und Management / Kurbel, K., Pietsch, W.},
  series = {Informatik-Spektrum. 12 (1989), H. 2},
  journal   = {Informatik-Spektrum. 12 (1989), H. 2},
  isbn      = {0170-6012},
  pages     = {133 -- 146},
  year      = {1989},
  language  = {de}
}
@article{HelsperMoelterKaminski1989,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Kaminski, S.},
  title     = {Fast and Automated Testing of Different Air Filter Media / M{\"o}lter, W. ; Helsper, C. ; Kaminski, S.},
  series = {1. Europ{\"a}isches Symposium Partikelabscheidung aus Gasen : [PARTEC, N{\"u}rnberg, West Germany, 19. - 21. April 1989 ; preprints] = 1. European Symposium Separation of Particles from Gases / [Organisation und Durchf{\"u}hrung: N{\"u}rnbergMesse]. Hrsg. von: Friedrich L{\"o}ffler},
  journal   = {1. Europ{\"a}isches Symposium Partikelabscheidung aus Gasen : [PARTEC, N{\"u}rnberg, West Germany, 19. - 21. April 1989 ; preprints] = 1. European Symposium Separation of Particles from Gases / [Organisation und Durchf{\"u}hrung: N{\"u}rnbergMesse]. Hrsg. von: Friedrich L{\"o}ffler},
  publisher = {N{\"u}rnbergMesse},
  address   = {N{\"u}rnberg},
  pages     = {441 -- 457},
  year      = {1989},
  language  = {en}
}
@article{HelsperMoelterKaminski1989,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Kaminski, S.},
  title     = {Fast and Automated Testing of Different Air Filter Media / M{\"o}lter, W. ; Helsper, C. ; Kaminski, S.},
  series = {Proceedings of the Filtech Conference, Karlsruhe 1989, Vol. 1},
  journal   = {Proceedings of the Filtech Conference, Karlsruhe 1989, Vol. 1},
  publisher = {Filtration Society},
  address   = {Oadby},
  pages     = {125 -- 136},
  year      = {1989},
  language  = {en}
}
@article{Lassonczyk1989,
  author    = {Lassonczyk, Beate},
  title     = {Fossile Bodenbildung in Nord-Somalia},
  series = {Mitteilungen der Deutschen Bodenkundlichen Gesellschaft. 59 (1989), H. 2},
  journal   = {Mitteilungen der Deutschen Bodenkundlichen Gesellschaft. 59 (1989), H. 2},
  isbn      = {0343-107x},
  pages     = {927 -- 930},
  year      = {1989},
  language  = {de}
}
@inproceedings{StaatBallmann1989,
  author    = {Staat, Manfred and Ballmann, J.},
  title     = {Fundamental aspects of numerical methods for the propagation of multi-dimensional nonlinear waves in solids},
  series = {Nonlinear hyperbolic equations : theory, computations methods, and applications ; proceedings of the 2nd International Conference on Nonlinear Hyperbolic Problems, Aachen},
  booktitle = {Nonlinear hyperbolic equations : theory, computations methods, and applications ; proceedings of the 2nd International Conference on Nonlinear Hyperbolic Problems, Aachen},
  pages     = {574 -- 588},
  year      = {1989},
  abstract  = {The nonlinear scalar constitutive equations of gases lead to a change in sound speed from point to point as would be found in linear inhomogeneous (and time dependent) media. The nonlinear tensor constitutive equations of solids introduce the additional local effect of solution dependent anisotropy. The speed of a wave passing through a point changes with propagation direction and its rays are inclined to the front. It is an open question whether the widely used operator splitting techniques achieve a dimensional splitting with physically reasonable results for these multi-dimensional problems. May be this is the main reason why the theoretical and numerical investigations of multi-dimensional wave propagation in nonlinear solids are so far behind gas dynamics. We hope to promote the subject a little by a discussion of some fundamental aspects of the solution of the equations of nonlinear elastodynamics. We use methods of characteristics because they only integrate mathematically exact equations which have a direct physical interpretation.},
  subject      = {Nichtlineare Welle},
  language  = {en}
}
@book{GrapRajapaksha1989,
  author    = {Grap, Rolf Dietmar and Rajapaksha, Rolf},
  title     = {Gestaltung menschengerechter Arbeitspl{\"a}tze in der Schulbuchproduktion / [Zsstellung des Berichts: Rolf Rajapaksha]},
  publisher = {Cornelsen},
  address   = {Berlin},
  pages     = {78 S.},
  year      = {1989},
  language  = {de}
}
@book{Grap1989,
  author    = {Grap, Rolf Dietmar},
  title     = {Gestaltung menschengerechter Arbeitspl{\"a}tze in der Schulbuchproduktion: Ergebnisse der Ist-Analyse - Arbeitswissenschaftlicher Teil},
  publisher = {IAW - Lehrstuhl und Institut f{\"u}r Arbeitswissenschaft der RWTH Aachen},
  address   = {Aachen},
  year      = {1989},
  language  = {de}
}
@book{Grap1989,
  author    = {Grap, Rolf Dietmar},
  title     = {Gestaltung menschengerechter Arbeitspl{\"a}tze in der Schulbuchproduktion: Vorschl{\"a}ge zum Sollkonzept - Arbeitswissenschaftlicher Teil},
  publisher = {IAW - Lehrstuhl und Institut f{\"u}r Arbeitswissenschaft der RWTH Aachen},
  address   = {Aachen},
  year      = {1989},
  language  = {de}
}
@misc{Wahle1989,
  author    = {Wahle, Michael},
  title     = {Gestaltung von plattenf{\"o}rmigen Hohlprofilen oder wellblechartigen Profilen : Offenlegungsschrift / Europ{\"a}ische Patentschrift},
  publisher = {Deutsches Patent- und Markenamt / Europ{\"a}isches Patentamt},
  address   = {M{\"u}nchen / Den Hague},
  pages     = {8 S. : graph. Darst.},
  year      = {1989},
  language  = {de}
}
@article{KotterHammonRiekert1989,
  author    = {Kotter, Michael and Hammon, Ulrich and Riekert, Lothar},
  title     = {Gewinnung niedriger Olefine aus Methanol bei partiellem Umsatz mit R{\"u}ckf{\"u}hrung / U. Hammon ; M. Kotter ; L. Riekert},
  series = {Chemie - Ingenieur - Technik. 61 (1989), H. 2},
  journal   = {Chemie - Ingenieur - Technik. 61 (1989), H. 2},
  isbn      = {0009-286X},
  pages     = {151 -- 152},
  year      = {1989},
  language  = {de}
}