1. Apple patent on http://www.touchuserinterface.com/2008/12/apple-patent-application-suggest-new.html
2. Arrows Keyboard on http://play.google.com/
3. R. C. Barrett, E. J. Selker, J. D. Rutledge, and R. S. Olyha. 1995. Negative inertia: a dynamic pointing function. Conference Companion on Human Factors in Computing Systems CHI 1995. ACM, 316--317.
4. Géry Casiez and Nicolas Roussel. 2011. No more bricolage!: methods and tools to characterize, replicate and compare pointing transfer functions. In Proceedings of UIST 2011. ACM, 603--614.
5. Andy Cockburn, David Ahlström, and Carl Gutwin. 2012. Understanding performance in touch selections: Tap, drag and radial pointing drag with finger, stylus and mouse. International Journal of Human-Computer Studies. 70, 3, 218--233.