J. Lienhard, und J. Knippers. Proceedings of the International IASS Symposium, International Association for Shell and Spatial Structures, (21-24 May 2012)
D. Park, J. Knippers, und K. Hwang. Conference proceeding of the 9th Asian Pacific Conference on Shell and Spatial Structures (APCS2009), Seite 31. Nagoya Japan, (Mai 2009)