D. Filho, E. Oliveira, L. Carvalho, M. Pessoa, F. Pereira, and D. Oliveira. " A data-driven analysis to assess the impact of an online judge's gamification on student performance", in Proceedings of the 31st Brazilian Symposium on Computers in Education, Online, 2020, pp. 491-500, doi: https://doi.org/10.5753/cbie.sbie.2020.491.