F. Mitzlaff, D. Benz, G. Stumme, and A. Hotho. Proceedings of the 21st ACM conference on Hypertext and hypermedia, page 265--270. New York, NY, USA, ACM, (2010)
F. Mitzlaff, M. Atzmueller, D. Benz, A. Hotho, and G. Stumme. Analysis of Social Media and Ubiquitous Data, volume 6904 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, (2011)