Gudrun Klinker Didier Stricker Dirk Reiners An Optically Based Direct Manipulation Interface for Human-Computer Interaction in an Augmented World. 53-62 1999 EGVE https://doi.org/10.1007/978-3-7091-6805-9_6 conf/egve/1999 db/conf/egve/egve1999.html#KlinkerSR99