Yusuf Aditya, Maulana. “The Use of ‘define it!’ Game in Teaching Descriptive Speaking”. SELL (Scope of English Language Teaching, Linguistics, and Literature) Journal, vol. 5, no. 1, Feb. 2020, pp. 40-46, http://publikasi.stkippgri-bkl.ac.id/index.php/SL/article/view/358.