Rerkrai, D. (1977). A comparison of two types of extension workers in Thailand according to certain aspects of their job [microform]. Photoduplication Service. University of the Philippines Library.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Rerkrai, Direk. A Comparison of Two Types of Extension Workers in Thailand According to Certain Aspects of Their Job [microform]. Quezon City: Photoduplication Service. University of the Philippines Library, 1977.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Rerkrai, Direk. A Comparison of Two Types of Extension Workers in Thailand According to Certain Aspects of Their Job [microform]. Photoduplication Service. University of the Philippines Library, 1977.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.