Sunit Kumar, Sushil Kumar and Rachna Kumari (2021) “An EPQ model with two-level trade credit and multivariate demand incorporating the effect of system improvement and preservation technology”, Malaya Journal of Matematik. India, 9(01), pp. 438–448. Available at: https://www.malayajournal.org/index.php/mjm/article/view/1055 (Accessed: 22 November 2024).