Huang, J., M. C. Chou, and C.-P. Teo. “Bike-Repositioning Using Volunteers: Crowd Sourcing With Choice Restriction”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 35, no. 13, May 2021, pp. 11844-52, doi:10.1609/aaai.v35i13.17407.