Citation:
Harpold, Terry. "Thick and Thin: 'Direct Manipulation' & The Spatial Regimes of Human-Computer Interaction." Proceedings of SIGGRAPH 2001. <http://www.siggraph.org/artdesign/gallery/S01/essays/0386.pdf>
Harpold, Terry. "Thick and Thin: 'Direct Manipulation' & The Spatial Regimes of Human-Computer Interaction." Proceedings of SIGGRAPH 2001. <http://www.siggraph.org/artdesign/gallery/S01/essays/0386.pdf>