Sumartika Br Hutasoit, Budi Serasi Ginting and Fuzi Yustika Manik (2022) “Grouping Library Book Collection Based On Old Book Borrowers With Clustering Method (Case study: STMIK Kaputama)”, International Journal of Health Engineering and Technology (IJHET), 1(2). doi: 10.55227/ijhet.v1i2.36.