1. CIA World Factbook 2015; https://www.cia.gov/library/publications/the-world-factbook/fields/2103.html CIA World Factbook 2015; https://www.cia.gov/library/publications/the-world-factbook/fields/2103.html
2. User Interface Design for Low-literate and Novice Users: Past, Present and Future
3. ITU Facts and Figures 2017.; https://www.itu.int/en/ITU-D/Statistics/Documents/facts/ICTFactsFigures2017.pdf ITU Facts and Figures 2017.; https://www.itu.int/en/ITU-D/Statistics/Documents/facts/ICTFactsFigures2017.pdf
4. UNICEF State of the World's Children 2017; https://www.unicef.org/publications/files/SOWC_2017_ENG_WEB.pdf. UNICEF State of the World's Children 2017; https://www.unicef.org/publications/files/SOWC_2017_ENG_WEB.pdf.