Rizki Ani Khairunnisa, A. B. A. Pradana, and A. E. Wardhana. “The Effect of Inside Outside Circle (IOC) Model by Using Flashcards towards students’ English Vocabulary Mastery”. Erudita: Journal of English Language Teaching, vol. 1, no. 1, Nov. 2021, pp. 54-64, doi:10.28918/erudita.v1i1.4303.