1. Andrade, F. R. H., Mizoguchi, R., & Isotani, S. (2016). The bright and dark sides of gamification (pp. 176–186). Intelligent Tutoring Systems Springer International Publishing.
2. Atchison, A. J. (2021, October 6). 3 Effective ways to use gamification to boost engagement. Retrieved March 2, 2022, from Business 2 Community website: https://www.business2community.com/strategy/3-effective-ways-to-use-gamification-to-boost-engagement-02434985
3. Aufreiter, N., Boudet, J., & Weng, V. (2015, July 24). Why marketers should keep sending you e-mails. Retrieved March 2, 2022, from Mckinsey.com website: https://www.mckinsey.com/business-functions/marketing-and-sales/our-insights/why-marketers-should-keep-sending-you-emails
4. Aydin, G. (2015). Adoption of gamified systems: A study on a social media gamification website. International Journal of Online Marketing (IJOM), 5(3), 18–37.
5. Bayliss, P. (2007). Beings in the game-world: characters, avatars, and players. In Proceedings of the 4th Australasian conference on Interactive entertainment (pp. 1–6).