Suprapti, Suprapti, et al. “Flipped Learning Instruction to Enhance University Students’ Higher Order Thinking Skills”. Jurnal Kependidikan: Jurnal Hasil Penelitian Dan Kajian Kepustakaan Di Bidang Pendidikan, Pengajaran Dan Pembelajaran, vol. 7, no. 2, June 2021, pp. 261-9, doi:10.33394/jk.v7i2.3320.