J. Zimmermann, S. Oliver, L. Wolfram, and O. Wolfgang. IFAC Symposium on Mechatronic Systems, 43, page 545--551. Cambridge, MA, USA, IFAC Proceeedings Volumes, (September 2010)
J. Neupert, E. Arnold, K. Knierim, O. Sawodny, and K. Schneider. ASME International Design Engineering Technical Conferences Computers and Information Engineering Conference IDETC/CIE, San Diego, California, USA, (2009)