1. Fundamentals of Game Design;Adams,2013
2. Axon, S., 2016. Unity at 10: For better—or worse—game development has never been easier | Ars Technica UK [WWW Document]. Arstechnica. URL https://arstechnica.co.uk/gaming/2016/09/unity-at-10-easy-game-development/ (accessed 9.2.17).
3. Educational software features that encourage and discourage “gaming the system,”;Baker,2009
4. Increasing engagement with the library via gamification;Barr,2016
5. Bartle, R., 1996. Richard a. bartle: players who suit MUDs [WWW document]. Mud.co.uk. URL http://mud.co.uk/richard/hcds.htm (accessed 9.14.17).