Hidayat, Wahyu, Mohammad Musab bin Azmat Ali, Nur Asmawati Lawahid, and Mujahidah Mujahidah. 2021. “Developing the Flipped Learning Instrument in an ESL Context: The experts’ Perspective”. Jurnal Penelitian Dan Evaluasi Pendidikan 25 (1):35-48. https://doi.org/10.21831/pep.v25i1.38060.