Ruja Pholsward และ Donrutai Boonprasitt. (2015) English Vocabulary Acquisition of Bilingual Learners at the Primary and Secondary Levels. <i>PASAA : a journal of language teaching and learning</i>, <i>49</i>, 1_38.Ruja Pholsward และ Donrutai Boonprasitt. "English Vocabulary Acquisition of Bilingual Learners at the Primary and Secondary Levels". PASAA : a journal of language teaching and learning 49 (2015):1_38.Ruja Pholsward และ Donrutai Boonprasitt. English Vocabulary Acquisition of Bilingual Learners at the Primary and Secondary Levels. สถาบันภาษา จุฬาลงกรณ์มหาวิทยาลัย:ม.ป.ท. 2015.