Chi, C., S. Zhang, J. Xing, Z. Lei, S. Z. Li, and X. Zou. “Relational Learning for Joint Head and Human Detection”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 34, no. 07, Apr. 2020, pp. 10647-54, doi:10.1609/aaai.v34i07.6691.