Daduna, H, Krenzler, R, Ritter, R & Stoyan, D 2018, ' Heuristic approximation and computational algorithms for closed networks : A case study in open-pit mining ' Performance Evaluation, vol 119, pp. 5-26 . DOI: 10.1016/j.peva.2017.12.002 Daduna, H, Krenzler, R, Ritter, R & Stoyan, D 2018, ' Heuristic approximation and computational algorithms for closed networks : A case study in open-pit mining ', Performance Evaluation, vol. 119, pp. 5-26 . https://doi.org/10.1016/j.peva.2017.12.002