Pohan, Nurmaliana, and Zulfitri Yani. “Inventory System Design Using Weight Average Cost (WAC) and Graphic Methods”. JURNAL TEKNOLOGI DAN OPEN SOURCE 6, no. 1 (June 19, 2023): 63 - 71. Accessed February 7, 2025. https://ejournal.uniks.ac.id/index.php/JTOS/article/view/3093.