Hauc, Anton, Majda Bastič, Lidia Jurše, and Mirko Pšunder. “Model for Optimal Project Portfolio for the Construction of Railway Infrastructure on Corridors V and X”. Promet - Traffic&Transportation 22, no. 1 (January 27, 2012): 29-41. Accessed August 14, 2020. https://traffic.fpz.hr/index.php/PROMTT/article/view/162.