P. Klügl, M. Toepfer, F. Lemmerich, A. Hotho, and F. Puppe. Proceedings of 1st International Conference on Pattern Recognition Applications and Methods ICPRAM, page 240-248. Vilamoura, Algarve, Portugal, SciTePress, (2012)
S. Doerfel, R. Jäschke, and G. Stumme. Formal Concept Analysis, volume 7278 of Lecture Notes in Artificial Intelligence, page 77--95. Berlin/Heidelberg, Springer, (May 2012)