Wang, X., Donaldson, R., Nell, C., Gorniak, P., Ester, M., & Bu, J. (2016). Recommending Groups to Users Using User-Group Engagement and Time-Dependent Matrix Factorization. Proceedings of the AAAI Conference on Artificial Intelligence, 30(1). https://doi.org/10.1609/aaai.v30i1.10160