R. Jäschke, and S. Rudolph. Contributions to the 11th International Conference on Formal Concept Analysis, page 19--34. Technische Universität Dresden, (May 2013)
S. Dietze. Proceedings of 2nd Workshop on Recommender Systems for Technology Enhanced Learning (RecSysTEL2012), at 7th European Conference on Technology-Enhanced Learning (EC-TEL 2012), CEUR-WS Vol. 896, Saarbrücken (2012), (2012)