Keliwar, Said, et al. “Modeling of Time Series Data for Forecasting the Number of Foreign Tourists in East Kalimantan Using Fuzzy Inference System Based on ARX Model”. International Journal of Engineering & Technology, vol. 7, no. 2.2, Mar. 2018, pp. 104-7, https://doi.org/10.14419/ijet.v7i2.2.12745.