Tangco, M. A. D. (1979). The effects of frustration on the flexibility of internals and externals [microform]. Photoduplication Service. University of the Philippines Library.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Tangco, Maria Angelita Dineros. The Effects of Frustration on the Flexibility of Internals and Externals [microform]. Quezon City: Photoduplication Service. University of the Philippines Library, 1979.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Tangco, Maria Angelita Dineros. The Effects of Frustration on the Flexibility of Internals and Externals [microform]. Photoduplication Service. University of the Philippines Library, 1979.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.