A. Kumar. Proceedings of the 2015 ACM Conference on Innovation and Technology in Computer Science Education - ITiCSE \textquotesingle15, page 314-319. ACM Press, (2015)
G. Nelson, B. Xie, and A. Ko. Proceedings of the 2017 ACM Conference on International Computing Education Research, page 2--11. New York, NY, USA, ACM, (2017)