Guidelines for multimodal user interface design.
Leah ReevesJennifer C. LaiJames A. LarsonSharon L. OviattT. S. BalajiStéphanie BuisinePenny CollingsPhilip R. CohenBen KraalJean-Claude MartinMichael F. McTearT. V. RamanKay M. StanneyHui SuQian Ying WangPublished in: Commun. ACM (2004)