Scholz, Christoph, Macek, Bjoern-Elmar, Atzmueller, Martin, Doerfel, Stephan and Stumme, Gerd. "Mining Social Links for Ubiquitous Knowledge Engineering." In Socio-technical Design of Ubiquitous Computing Systems , edited by Klaus David, Kurt Geihs, Jan Marco Leimeister, Alexander Roßnagel, Ludger Schmidt, Gerd Stumme and Arno Wacker , 109-129. : Springer International Publishing, 2014.

Manning, Christopher D., Raghavan, Prabhakar and Schütze, Hinrich. Introduction to Information Retrieval. New York: Cambridge University Press, 2008.

de Nooy, Wouter, Mrvar, Andrej and Batagelj, Vladimir. Exploratory Social Network Analysis with Pajek (Structural Analysis in the Social Sciences). illustrated edition : Cambridge University Press, 2005.

Diestel, Reinhard. Graph Theory. 3 (electronic edition) : Springer-Verlag Heidelberg, New York, 2005.