sunanta, ketsarin, A. Preedeekun, and W. Pongarjarn. “The Construction of English Learning Package on Project Based Learning to Develop English Communicative Competence for Grade 6 Students”. Humanities and Social Sciences Journal of Pibulsongkram Rajabhat University, vol. 11, no. 2, Nov. 2016, pp. 106-19, https://so01.tci-thaijo.org/index.php/GraduatePSRU/article/view/64340.