F. Balderas, E. Fernandez, C. Gómez, L. Cruz-Reyes, and N. Rangel-Valdez, “Metaheuristic Robust Optimization of Project Portfolios using an Interval-Based Model of Imprecisions”, Int. Journal of COP and Infor., vol. 7, no. 3, pp. 101–118, Nov. 2016.