Wulandari, R., B. Surarso, B. Irawanto, and F. Farikhin. “The Forecasting of Palm Oil Based on Fuzzy Time Series-Two Factor”. Journal of Soft Computing Exploration, vol. 2, no. 1, Mar. 2021, pp. 11-16, https://www.shmpublisher.com/index.php/joscex/article/view/14.