Rojas-Trejos, Carlos Alberto, Julián González-Velasco, and Mario Alberto López-Ramírez. 2018. “Optimization Model for the Location of Prehospital Care Ambulances in the City of Cali Colombia”. International Journal of Combinatorial Optimization Problems and Informatics 8 (3):64-70. https://ijcopi.org/ojs/article/view/20.