“Optimal Configuration Design for a Multi –stage System Model”. Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ) 25, no. 2 (October 24, 2021): 185–204. Accessed May 13, 2026. https://jrucs.iq/index.php/JAUCS/article/view/456.