Oryza Safitri, and Mardlijah. “ontrol ptimum ada odel rey-redator engan emanenan ada kan rey an kan redator”. imits: ournal of athematics and ts pplications, vol. 16, no. 1, Aug. 2019, pp. 39-49, https://journal.its.ac.id/index.php/limits/article/view/5397.