Dickerson, J. P., K. A. Sankararaman, A. Srinivasan, and P. Xu. “Balancing Relevance and Diversity in Online Bipartite Matching via Submodularity”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 33, no. 01, July 2019, pp. 1877-84, doi:10.1609/aaai.v33i01.33011877.