Thomas Butkiewicz, Andrew H. Stevens, Colin Ware. Multi-touch 3D positioning with the pantograph technique. In Stephen N. Spencer, Sheldon Andrews, Natalya Tatarchuk, editors, Proceedings of the ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, I3D 2019, Montreal, QC, Canada, May 21-23, 2019. ACM, 2019. [doi]