1. Adeli H.: Knowledge Engineering. McGraw-Hill. New-York. (1994)
2. Aussenac-Gilles N., Natta N.: Making the Method Solving Explicit with MACAO: SIZYPHUS Case-Study. In: Linster M. (Ed.): Sisyphus'92: Models of problem solving, GMD-Arbeitspapiere. (1993) 1–21
3. Boose J.H.: Knowledge Acquisition Tools, Methods and Mediating Representations. In: Motoda H., Mizogochi R., Boose J., Gaines B. (Eds.): Knowledge Acquisition for Knowledge-Based Systems, IOS Press, Ohinsha Ltd., Tokyo. (1990) 123–168
4. Brusilovsky P., Schwarz E.: User as Student: Towards an Adaptive Interface for Advanced Web-based Applicaions. Proc. of Sixth Int Conf. On User Modeling UM'97, Springer Wien. (1997) 177–188
5. Eisenstadt M., Domingue J., Rajan T., Motta E: Visual Knowledge Engineering. IEEE Transactions on Software Engineering, Vol.16, No.10. (1990) 1164–1177