F. Lemmerich, M. Becker, P. Singer, D. Helic, A. Hotho, and M. Strohmaier. Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, page 965–974. New York, NY, USA, Association for Computing Machinery, (2016)
R. Jäschke, A. Hotho, F. Mitzlaff, and G. Stumme. Recommender Systems for the Social Web, volume 32 of Intelligent Systems Reference Library, Springer, Berlin/Heidelberg, (2012)