“Estimation of the Optimum Period for the Replacement of Machines Using the Age Replacement Model Under the Minimum Cost Criterion”. Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ) 52, no. 2 (December 31, 2022): 1–10. Accessed April 16, 2026. https://jrucs.iq/index.php/JAUCS/article/view/537.