Chen, Yiwei, Jingwen Qian, Junming Wang, Lirong Xia, and Gavriel Zahavi. 2021. “OPRA: An Open-Source Online Preference Reporting and Aggregation System”. Proceedings of the AAAI Conference on Artificial Intelligence 35 (18):16011-13. https://doi.org/10.1609/aaai.v35i18.17996.