Literature to start with:
[Fontana16] F. Arcelli Fontana, M. V. M ̈antyl ̈a, M. Zanoni, and A. Marino, “Comparing and experimenting machine learning techniques for code smell detection,” Empirical Software Engineering, vol. 21, pp. 1143–1191, 6 2016.
[Choetkiertikul18] M. Choetkiertikul, H. K. Dam, T. Tran, T. Pham, A. Ghose, and T. Menzies, “A deep learning model for estimating story points,” IEEE Transactions on Software Engineering, vol. PP, no. 99, pp. 1–1, 2018.
[Habayeb18] M. Habayeb, S. S. Murtaza, A. Miranskyy, and A. B. Bener, “On the use of hidden markov model to predict the time to fix bugs,” IEEE Transactions on Software Engineering, vol. 44, pp. 1224–1244, Dec 2018.