@articlePeckhaus_1991, title=Ernst Schröder und die ,pasigraphischen Systeme‘ von Peano und Peirce, volume=1, number=2/3, journal=Modern Logic, author=Peckhaus, Volker, year=1991, pages=174–205 

@inproceedingsPeckhaus_1991, place=o.O.u.J. (Uppsala), title=Logic in Transition: The Logical Calculi of Hilbert (1905) and Zermelo (1908) [Abstract], booktitle=Abstracts of the 9th International Congress of Logic, Methodology and Philosophy of Science, Uppsala, August 7–14, 1991, Bd. 2: General Philosophy of Science. Sections 6–9, author=Peckhaus, Volker, year=1991, pages=158 

@inproceedingsMüller_1991, place=Grassau Germany, title=Contract-Oriented System Design and Specification, booktitle=Proceedings of the Workshop on Practical Computer Based Systems Engineering - its Scope and Methods, author=Müller, Wolfgang, year=1991 

@inproceedingsLehrenfeld_Müller_1991, place=Houston TX, USA, title=Validation of EXPRESS Models Using Prolog, booktitle=Proceedings of the 1st EXPRESS User’s Group Conference, author=Lehrenfeld, Georg and Müller, Wolfgang, year=1991 

@inbookSchroeter-Wittke_1991, place=Gütersloh, title=Letzter Sonntag nach Epiphanias; Predigttext: 2. Korinther 4,6-10, volume=132–139, booktitle=Gottesdienstpraxis. Serie A. II. Perikopenreihe Band 1, publisher=Gütersloher Verlagshaus, author=Schroeter-Wittke, Harald, editor=Nitschke, Horst, year=1991 

@inproceedingsGoser_Hilleringmann_Rückert_1991, place=Berlin, Heidelberg, title=Application and implementation of neural networks in microelectronics, booktitle=Artificial Neural Networks, publisher=Springer Berlin Heidelberg, author=Goser, K. and Hilleringmann, Ulrich and Rückert, U., editor=Prieto, Alberto, year=1991, pages=243–259 

@inbookEke_1990, place=Gütersloh, München, title=Maximilian von Löwenthal, volume=7, booktitle=Literatur Lexikon. Autoren und Werke deutscher Sprache. Bd. 7, author=Eke, Norbert Otto, editor=Killy, WaltherEditor, year=1990, pages=332 

@inbookAlt_Blömer_Wagener_1990, place=Berlin/Heidelberg, title=Approximation of convex polygons, DOI=10.1007/bfb0032068, booktitle=Automata, Languages and Programming, publisher=Springer-Verlag, author=Alt, Helmut and Blömer, Johannes and Wagener, Hubert, year=1990, pages=703–716 

@bookPeckhaus_1990, place=Göttingen, series=Studien zur Wissenschafts-, Sozial- und Bildungsgeschichte der Mathematik, title=Hilbertprogramm und Kritische Philosophie. Das Göttinger Modell interdisziplinärer Zusammenarbeit zwischen Mathematik und Philosophie, volume=7, publisher=Vandenhoeck &; Ruprecht, author=Peckhaus, Volker, year=1990, collection=Studien zur Wissenschafts-, Sozial- und Bildungsgeschichte der Mathematik 

@bookEke_Oellers_Skrodzki_Steinecke_1990, place=Wien, title=Nikolaus Lenau. Werke und Briefe. Historisch-kritische Gesamtausgabe. Bd. 6,1: Briefe 1838-1847. Teil 1: Text (Edition), publisher=Österreichischer Bundesverlag, Klett-Cotta, author=Eke, Norbert Otto and Oellers, Norbert and Skrodzki, Karl Jürgen and Steinecke, Hartmut, year=1990 

@inproceedingsHohenstein_Engels_1990, title=Formal Semantics of an Entity-Relationship Query Language, booktitle=Proceedings of the 9th International Conference on Entity-Relationship Approach (ER 90), Lausanne, Switzerland, publisher=ER Institute, author=Hohenstein, Uwe and Engels, Gregor, year=1990, pages=177–188 

@inproceedingsKrauter_Hanitsch_1990, title=The Influence of the Capsulation on the Efficiency of PV-Modules., DOI=10.1016/B978-0-08-037539-7.50062-4, booktitle=Proceedings of the 1st World Renewable Energy Congress, Reading (UK), 23.–28. September 1990, Band 1, S. 141–144., author=Krauter, Stefan and Hanitsch, Rolf, year=1990 

@inproceedingsEngels_1990, place=Berlin/Heidelberg, title=Elementary Actions on an Extended Entity-Relationship Database, volume=532, DOI=http://dx.doi.org/10.1007/BFb0017372, booktitle=Proceedings of the workshop on Graph Grammars and Their Application to Computer Science (1990), Bremen (Germany), publisher=Springer, author=Engels, Gregor, year=1990, pages=344–362 

@inbookDietzfelbinger_Meyer auf der Heide_1990, place=Berlin/Heidelberg, title=A new universal class of hash functions and dynamic hashing in real time, DOI=10.1007/bfb0032018, booktitle=Automata, Languages and Programming, author=Dietzfelbinger, Martin and Meyer auf der Heide, Friedhelm, year=1990 

@inbookMeyer auf der Heide_1990, place=Berlin/Heidelberg, title=Dynamic hashing strategies, DOI=10.1007/bfb0029597, booktitle=Lecture Notes in Computer Science, author=Meyer auf der Heide, Friedhelm, year=1990 

@inbookKarpinski_Meyer auf der Heide_1990, place=Berlin/Heidelberg, title=On the complexity of genuinely polynomial computation, DOI=10.1007/bfb0029630, booktitle=Lecture Notes in Computer Science, author=Karpinski, Marek and Meyer auf der Heide, Friedhelm, year=1990 

@inproceedingsDietzfelbinger_Meyer auf der Heide_1990, title=How to distribute a dictionary in a complete network, DOI=10.1145/100216.100229, booktitle=Proceedings of the twenty-second annual ACM symposium on Theory of computing  - STOC ’90, author=Dietzfelbinger, M. and Meyer auf der Heide, Friedhelm, year=1990 

@inproceedingsGil_Meyer auf der Heide_Wigderson_1990, title=Not all keys can be hashed in constant time, DOI=10.1145/100216.100247, booktitle=Proceedings of the twenty-second annual ACM symposium on Theory of computing  - STOC ’90, author=Gil, J. and Meyer auf der Heide, Friedhelm and Wigderson, A., year=1990 

@articleMeyer auf der Heide_1990, title=Das Heinz Nixdorf-Institut der Universität-GH Paderborn, volume=13, number=4, journal=Informatik Spektrum, author=Meyer auf der Heide, Friedhelm, year=1990, pages=231–232 

@inproceedingsDomik_Brugel_Stencel_1990, series=BAAS, title=IRAS On-Line Catalogs at CASA, volume=Vol. 22, number=No. 2, booktitle=Proceedings of the 176th meeting of the American Astronomical Society, author=Domik, Gitta and Brugel, E.W. and Stencel, R.E., year=1990, collection=BAAS