1. Research on the Game Elements and Mechanism that Affect the Game Overindulgence and Addiction
2. M. Csikszentmihalyi, Creativity: Flow and the psychology of discovery and invention , Harper Perennial, New York, May 1997.
3. H. Yoon, “A Study on Analysis of a Serious Game: A Online Game “Allep””, Journal of The Korean Society for Computer Game, Vol. 24, No. 2, pp. 33-42, Jun. 2011.
4. E. Lee, A study on development of mathematic edutainment for middle and high school student : fits the curriculum of the middle school, Master’s Thesis, Chung-Ang University, Seoul, Feb. 2016.
5. Developing a Subset Sum Problem based Puzzle Game for Learning Mathematical Programming