Expósito-Izquierdo, C., B. Melián-Batista, and J. M. Moreno-Vega. “Optimization Model and Heuristic Approach for Blocks Retrieval Processes in Warehouses”. Proceedings of the International Conference on Automated Planning and Scheduling, vol. 24, no. 1, May 2014, pp. 111-9, doi:10.1609/icaps.v24i1.13634.