Changes

Plaisant, Catherine [http://www.cs.umd.edu/hcil/touchscreens/ "High-Precision TouchScreens 1988-1991 HCIL Research"]

Saffer, Dan [http://www.kickerstudio.com/blog/2011/01/activity-zones-for-touchscreen-tablets-and-phones/ "Activity Zones for touchscreen tables and phones"]