Atira, Afifa, and Betha Sari. 2023. “The Application of Silhouette Coefficient, Elbow Method, and Gap Statistics for Determining the Optimal Clusters in Grouping Provinces in Indonesia Based on Happiness Index”. Jurnal Ilmiah Wahana Pendidikan 9 (17), 76-86. https://doi.org/10.5281/zenodo.8282638.