1. O. Kwon, K. Yoo and E. Suh, "ubiES: An intelligent expert system for proactive services deploying ubiquitous computing technologies", Proceedings of the 38th Hawaii International Conference on System Sciences, Big Island, HI, USA., vol. 28, n.° 1, pp. 149-161, 2005.
2. C.T. Fosnot, R.S. Perry, "Constructivism: A psychological theory of learning", in Constructivism: Theory, perspectives and practice 2nd ed., pp. 8-38, New York: Teacher's College Press, 2005.
3. C.-H. Tsai and J.-Y. Huang, "A mobile augmented reality based scaffolding platform for outdoor fieldtrip learning", in Proceedings of the 3rd International Conference on Advanced Applied Informatics, pp. 307-312, 2014. DOI: 10.1109/IIAI-AAI.2014.70
4. G. Hwang, C. Tsai, and S. YANG, "Criteria, Strategies and Research Issues of Context-Aware Ubiquitous Learning", Educational Technology & Society, vol. 11, n.° 2, pp. 81-91, 2008.
5. R. Kalaivani and R. Sivakumar, "A survey on context-aware ubiquitous learning systems", International Journal of Control Theory and Applications, vol. 10, n.° 23, pp. 111- 124, 2017.