“Estimation of the Optimum Period for the Replacement of Machines Using the Age Replacement Model Under the Minimum Cost Criterion” (2022) Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ), 52(2), pp. 1–10. doi:10.55562/jrucs.v52i1.537.