M. Atzmueller, S. Doerfel, A. Hotho, F. Mitzlaff, and G. Stumme. Modeling and Mining Ubiquitous Social Media - International Workshops MSM 2011, Boston, MA, USA, October 9, 2011, and MUSE 2011, Athens, Greece, September 5, 2011, Revised Selected Papers, volume 7472 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, Heidelberg, Germany, (2012)