P. Haase, A. Hotho, L. Schmidt-Thieme, and Y. Sure. Proceedings of the 3rd International Conference on Universal A ccess in Human-Computer Interaction (UAHCI), Las Vegas, Nevada USA, (22-27 July 2005)
S. Kaasten, and S. Greenberg. CHI '01: CHI '01 extended abstracts on Human factors in computing systems, page 379--380. New York, NY, USA, ACM Press, (2001)
H. Takano, and T. Winograd. HYPERTEXT '98: Proceedings of the ninth ACM conference on Hypertext and hypermedia : links, objects, time and space---structure in hypermedia systems, page 297--298. New York, NY, USA, ACM Press, (1998)