1. A survey on the use of mobile applications for people who are visually impaired;Griffin-Shirley;Journal of Visual Impairment & Blindness,2017
2. Advantages and Drawbacks of Smartphones and Tablets for Visually Impaired People: Analysis of ICT User Survey Results;Watanabe;IEICE Trans. Inf. Syst.,2015
3. https://www.statista.com/statistics/330695/number-of-smartphone-users-worldwide/.
4. https://www.bankmycell.com/blog/how-many-phones-are-in-the-world.
5. Comscore MMX® Multi-Platform, Total Minutes, June 2017 – June 2019, Multiple Countries. Available from: https://www.comscore.com/Insights/Presentations-and-Whitepapers/2019/Global-State-of-Mobile.