Penny, J. S. (1986). The Petchabun Piedmont survey: A initial investigation of the presistory of the western borders of the Khorat Plateau, Northeast Thailand. University of Pennsylvania.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Penny, James Sterling. The Petchabun Piedmont Survey: A Initial Investigation of the Presistory of the Western Borders of the Khorat Plateau, Northeast Thailand. Philadelphia: University of Pennsylvania, 1986.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Penny, James Sterling. The Petchabun Piedmont Survey: A Initial Investigation of the Presistory of the Western Borders of the Khorat Plateau, Northeast Thailand. University of Pennsylvania, 1986.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.