Chien, S., D. Tran, G. Rabideau, S. Schaffer, D. Mandl, and S. Frye. “Timeline-Based Space Operations Scheduling With External Constraints”. Proceedings of the International Conference on Automated Planning and Scheduling, vol. 20, no. 1, May 2010, pp. 34-41, doi:10.1609/icaps.v20i1.13410.