1. Cisco Visual Networking Index: Forecast and Methodology, 2014–2019 White Paper.
http://www.cisco.com/c/en/us/solutions/collateral/service-provider/ip-ngn-ip-next-generation-network/white_paper_c11-481360.html
. Accessed 30 Apr 2017
2. Statistical distribution of time spent on apps on mobile devices in the United States in June 2015, by category.
http://www.statista.com/statistics/248343/distribution-of-time-s pent-ios-and-android-apps-by-category
. Accessed 30 June 2015
3. Katie A, Siek Y, Rogers, Kay H, Connelly (2005) Fat finger worries: how older and younger users physically interact with pdas. In: Proceedings the 2005 IFIP TC13 international conference Human–computer interaction (INTERACT), pp. 267–280
4. Mitsuhiro Y, Akihiko M, Mahilum JBKT (2013) Moving IME panel for text input method and Shapekey prototype. In: 2013 IEEE 2nd global conference on consumer electronics (GCCE), pp. 474–478
5. Hall A, Cunningham J, Roache R, Cox J (1988) Factors affecting performance using touch-entry systems: tactual recognition fields and systems accuracy. J Appl Psychol 73:711–720