R. Rohini, K. Krishnan. Analysis of Two-Echelon Inventory System With Two Demand Classes With Direct Demand. Int. J. Math. And Appl. [Internet]. 2018 Sep. 15 [cited 2025 Nov. 4];6(3):261-7. Available from: https://ijmaa.in/index.php/ijmaa/article/view/379