Jonperson Tamba, R. Refiza, and Rizkha Rida. “PENGUKURAN HUMAN KAPITAL KARYAWAN DENGAN MENGGUNAKAN METODE RETURN ON INVESTMENT DI PT. XYZ TANJUNG MORAWA MEDAN”. Journal of Innovation Research and Knowledge, vol. 5, no. 5, Oct. 2025, pp. 5323-30, https://www.bajangjournal.com/index.php/JIRK/article/view/11390.