H. Hoppe, C. Kübler, J. Raczkowsky, and H. Wörn. Bildverarbeitung für die Medizin, volume 56 of CEUR Workshop Proceedings, page 229-232. Springer, (2002)
S. Kubler, M. Madhikermi, A. Buda, and K. Främling. MobiQuitous, volume 131 of Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, page 743-747. Springer, (2013)