Darakorn Phensiri. 1999. English language use of Thai government officials in the Ministry of Education. Bangkok:National Institute of Development Administration;
Darakorn Phensiri. (1999) English language use of Thai government officials in the Ministry of Education (รายงานผลงานวิจัย). National Institute of Development Administration:Bangkok.
Darakorn Phensiri. English language use of Thai government officials in the Ministry of Education. Bangkok:National Institute of Development Administration, 1999.
Darakorn Phensiri. (1999) English language use of Thai government officials in the Ministry of Education (รายงานผลงานวิจัย). National Institute of Development Administration:Bangkok.