P. Vorst, and A. Zell. European Robotics Symposium 2008, volume 44/2008 of Springer Tracts in Advanced Robotics, page 273-282. Springer Berlin / Heidelberg, (February 2008)
P. Vorst, and A. Zell. ISR/ROBOTIK 2010 (Proceedings of the joint conference of ISR 2010 (41st International Symposium on Robotics) and ROBOTIK 2010 (6th German Conference on Robotics)), page 354--361. VDE Verlag, (June 2010)