S. Kelle, S. Sigurðarson, W. Westera, and M. Specht. E-Infrastructures and Technologies for Lifelong Learning: Next Generation Environments, IGI Global, Hershey, PA, (2010)
M. Chatti, M. Jarke, T. Indriasari, and M. Specht. Learning in the Synergy of Multiple Disciplines, Proceedings of the EC-TEL 2009, volume 5794 of Lecture Notes in Computer Science, Berlin/Heidelberg, Springer, (October 2009)