KHATUA, D., and K. MAITY. “RESEARCH ON RELATIONSHIP BETWEEN ECONOMICAL PROFIT AND ENVIRONMENTAL POLLUTION OF IMPERFECT PRODUCTION INVENTORY CONTROL PROBLEM”. Journal of the Nigerian Mathematical Society, vol. 35, no. 3, Jan. 2017, pp. 560-79, https://ojs.ictp.it/jnms/index.php/jnms/article/view/49.