Yasuhiro Yamamoto Kumiyo Nakakoji Atsushi Aoki Spatial Hypertext for linear-information authoring: Interaction design and system development based on the ART Design principle. 35-44 2002 conf/ht/2002 Hypertext http://doi.acm.org/10.1145/513338.513351 db/conf/ht/ht2002.html#YamamotoNA02