Nghiem Van Tinh, Bui Thi Thi. Determining interval lengths for fuzzy time series forecasting model based on index of fuzzy sets by combining hedge algebra and particle swarm optimization. JMST [Internet]. 2023 Dec. 10 [cited 2024 Nov. 23];(FEE):271-82. Available from: https://online.jmst.info/index.php/jmst/article/view/1065