Sitanggang, Cansa Namira, and Maslathif Dwi Purnomo. “Indonesian EFL Students’ Perspective on Free4Talk: A Novice Vs. Expert User Study”. Jurnal Onoma: Pendidikan, Bahasa, Dan Sastra, vol. 11, no. 3, Aug. 2025, pp. 3783-96, doi:10.30605/onoma.v11i3.6844.