M. Kibanov, M. Atzmueller, C. Scholz, and G. Stumme. Cyber, Physical and Social Computing (CPSCom), 2013 IEEE International Conference on, Los Alamitos, CA, USA, IEEE Computer Society, (2013)
R. Jäschke, A. Hotho, C. Schmitz, and G. Stumme. Proc. 18. Workshop Grundlagen von Datenbanken, page 80-84. Halle-Wittenberg, Martin-Luther-Universität, (June 2006)