2Sears A, Plasisant C, Shneideman B. A new ear for high precision touchscreen, Advances of Human Computer Interaction [ M 1. New Jersey : Ablex, 1991 : 1 -33.
3Westerman W, Elias J G. Multi - touch screen[ C]. Proc Human Fact Ergonomics Soc. 45th Meeting[ S. I. ] : [ s. n. ] ,1991:632 -636.