Husein , A. M. ., F. K. . waruwu, Y. M. . Batu Bara, M. . Donpril, and M. Harahap. “Clustering Algorithm For Determining Marketing Targets Based Customer Purchase Patterns And Behaviors”. Sinkron : Jurnal Dan Penelitian Teknik Informatika, vol. 5, no. 2B, Oct. 2021, pp. 137-43, doi:10.33395/sinkron.v6i1.11191.