Arif Pratiwindyo. “The T.R.E.E Principles ”. Ideguru: Jurnal Karya Ilmiah Guru 4, no. 1 (October 1, 2019): 22-34. Accessed March 29, 2024. https://jurnal-dikpora.jogjaprov.go.id/index.php/jurnalideguru/article/view/79.