©2013 National Research Council of Thailand
Pornnapa Kosakul. 2007. The effect of pronunciation instruction on adult thai learners' pronunciation variation of -ed tense markers. Bangkok:Thammasat University 2007;
Pornnapa Kosakul. (2007) The effect of pronunciation instruction on adult thai learners' pronunciation variation of -ed tense markers (รายงานผลงานวิจัย). Thammasat University 2007:Bangkok.
Pornnapa Kosakul. The effect of pronunciation instruction on adult thai learners' pronunciation variation of -ed tense markers. Bangkok:Thammasat University 2007, 2007.
Pornnapa Kosakul. (2007) The effect of pronunciation instruction on adult thai learners' pronunciation variation of -ed tense markers (รายงานผลงานวิจัย). Thammasat University 2007:Bangkok.