N. A. . Fitri, M. N. . Hayati, and R. . Goejantoro, “Grouping Districts/Cities in Kalimantan Island Based on The People’s Welfare Indicators Using Fuzzy C-Means and Subtractive Fuzzy C-Means Methods”, JMSK, vol. 18, no. 1, pp. 141-149, Sep. 2021.