Thanannatthaphak, P., and T. Palanukulwong. “Thai Business English Students’ Receptive Vocabulary Size and Its Relationship to the Use of Vocabulary Learning Strategies”. KASEM BUNDIT JOURNAL, vol. 18, no. October, Dec. 2017, pp. 38-52, https://so04.tci-thaijo.org/index.php/jkbu/article/view/101477.