1. Perrin A, Duggan, M. American’s internet access: 2000-2015. 2015. Available at: http://www.pewinternet.org/2015/06/26/americans-internet-access-2000-2015/. Accessed March 1, 2018.
2. Smith A. Smartphone ownership. 2013. Available at: http://www.pewinternet.org/2013/06/05/smartphone-ownership-2013/. Accessed March 1, 2018.
3. Smith, A. U.S. Smartphone use in 2015. 2015. Available at: http://www.pewinternet.org/2015/04/01/us-smartphone-use-in-2015/. Accessed March 1, 2018.
4. Cook and hussey's assistive technologies: principles and practice;Cook,2008
5. A memory aid with remote communication: preliminary findings;Szymkowiak;Technol Disabil,2005