Paul P. Maglio Teenie Matlock Christopher S. Campbell Shumin Zhai Barton A. Smith Gaze and Speech in Attentive User Interfaces. 1-7 http://link.springer.de/link/service/series/0558/bibs/1948/19480001.htm 2000 conf/icmi/2000 ICMI db/conf/icmi/icmi2000.html#MaglioMCZS00