1. BBC News 2004 China Mobiles Outstrip Landlines http://news.bbc.co.uk/1/hi/business/3374893.stm
2. Central Intelligence Agency 2007 The World Factbook https://www.cia.gov/library/publications/the-world-factbook/
3. Concept and design of Ad Hoc and mobile classrooms;Chang;Journal of Computer Assisted Learning,2003
4. A mobile learning system for scaffolding bird watching learning;Chen;Journal of Computer Assisted Learning,2003
5. De Crom E.P. De Jager A. 2005 The ‘ME’-learning Experience: PDA Technology and E-Learning in Ecotourism at the Tshwane University of Technology (TUT) http://www.mlearn.org.za/papers-full.html