J. Coplien. Proceedings of the 2nd European Conference on Pattern Languages of Programming (EuroPLoP '97). Siemens Technical Report 120/SW1/FB, стр. 51-60. Munich, Germany, Siemens, (1997)
V. Devedzic, J. Good, A. Harrer, R. Luckin, D. Pearce, S. Retalis, и J. Robertson. Artificial Intelligence in Education - Building Technology Rich Learning Contexts that Work, том 158 из Frontiers in Artificial Intelligence and Applications, стр. 715. Amsterdam, IOS Press, (2007)