“Comparison of Forecasting Using Fuzzy Time Series Chen Model and Lee Model to Closing Price of Composite Stock Price Index”. UNP Journal of Statistics and Data Science 1, no. 2 (March 8, 2023): 74–81. Accessed October 1, 2026. https://ujsds.ppj.unp.ac.id/index.php/ujsds/article/view/22.