“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 ), vol. 52, no. 2, Dec. 2022, pp. 1-10, https://doi.org/10.55562/jrucs.v52i1.537.