M. Knuth, N. Ludwig, L. Wolf, and H. Sack. Proc. of the Second International Workshop on Mining Ubiquitous and Social Environments - MUSE'11, page 43--53. Athens, Greece, (September 2011)
J. Waitelonis, N. Ludwig, M. Knuth, and H. Sack. International Journal of Interactive Technology and Smart Education (ITSE), Special Issue on Multimedia technologies for e-learning, 8 (4):
236--248(2011)