Somsak Boonsathorn. n.d. Bias-free writing : an awareness of nonsexist usage in English. Bangkok:National Institute of Development Administration;
Somsak Boonsathorn. (n.d.) Bias-free writing : an awareness of nonsexist usage in English (รายงานผลงานวิจัย). National Institute of Development Administration:Bangkok.
Somsak Boonsathorn. Bias-free writing : an awareness of nonsexist usage in English. Bangkok:National Institute of Development Administration, n.d.
Somsak Boonsathorn. (n.d.) Bias-free writing : an awareness of nonsexist usage in English (รายงานผลงานวิจัย). National Institute of Development Administration:Bangkok.