Halls, W. D. (1971). International equivalences in access to higher education: A study of problems with special reference to selected countries. Unesco.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Halls, W. D. International Equivalences in Access to Higher Education: A Study of Problems with Special Reference to Selected Countries. Paris: Unesco, 1971.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Halls, W. D. International Equivalences in Access to Higher Education: A Study of Problems with Special Reference to Selected Countries. Unesco, 1971.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.