Ryuhei Tenmoku Yusuke Yoshida Fumihisa Shibata Asako Kimura Hideyuki Tamura Visually Elegant and Robust Semi-Fiducials for Geometric Registration in Mixed Reality. 261-262 2007 ISMAR http://dx.doi.org/10.1109/ISMAR.2007.4538857 conf/ismar/2007 db/conf/ismar/ismar2007.html#TenmokuYSKT07