Sidharta, I. “The Intellectual, Social, Affective Engagement Scale (ISA Engagement Scale) : A Validation Study”. Jurnal Computech &Amp; Bisnis (e-Journal), vol. 13, no. 1, June 2019, pp. 50-57, https://jurnal.stmik-mi.ac.id/index.php/jcb/article/view/114.