K. Becker, G. Stumme, R. Wille, U. Wille, and M. Zickwolff. Knowledge Engineering and Knowledge Management Methods, Models, and Tools, volume 1937 of Lecture Notes in Computer Science, Springer, Berlin/Heidelberg, (2000)
G. Stumme, R. Wille, and U. Wille. Principles of Data Mining and Knowledge Discovery, volume 1510 of Lecture Notes in Computer Science, Springer, Berlin/Heidelberg, (1998)
J. Hereth, G. Stumme, R. Wille, and U. Wille. Conceptual Structures: Logical, Linguistic, and Computational Issues, volume 1867 of Lecture Notes in Computer Science, Springer, Berlin/Heidelberg, (2000)
J. Hereth, G. Stumme, R. Wille, and U. Wille. Conceptual Structures: Logical, Linguistic, and Computational Issues. Proc. ICCS '00, volume 1867 of LNAI, page 421-437. Heidelberg, Springer, (2000)
F. Lehmann, and R. Wille. Conceptual structures: applications, implementation and theory, volume 954 of Lecture Notes in Artificial Intelligence, page 32-43. London, UK, Springer Verlag, (1995)