Susilowati, T., D. Sugiarto, and I. Mardianto. “Validity Test of Self-Organizing Map (SOM) and K-Means Algorithm for Employee Grouping”. Jurnal RESTI (Rekayasa Sistem Dan Teknologi Informasi), Vol. 4, no. 6, Dec. 2020, pp. 1171 -, doi:10.29207/resti.v4i6.2492.