1 Aug 2004 / Proceedings of the International Workshop {"}Interactive Computer aided Learning{"} ICL 2003. Learning Objects and Reusability of Content, Kassel University Press 2003, ISBN 3-89958-029-X
1 Aug 2004 / Proceedings of the International Workshop "Interactive Computer aided Learning" ICL 2002. Blended Learning. Kassel University Press 2002, ISBN 3-933146-83-6