Harahap, A. M. (2012). Political participation: A comparative sudy of undergraduate students in the Departments of Political Science and English Language and Literature. Kulliyyah of Islamic Revealed Knowledge and Human Sciences, International Islamic University Malaysia.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Harahap, Ali Musa. Political Participation: A Comparative Sudy of Undergraduate Students in the Departments of Political Science and English Language and Literature. Kuala Lumpur: Kulliyyah of Islamic Revealed Knowledge and Human Sciences, International Islamic University Malaysia, 2012.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Harahap, Ali Musa. Political Participation: A Comparative Sudy of Undergraduate Students in the Departments of Political Science and English Language and Literature. Kulliyyah of Islamic Revealed Knowledge and Human Sciences, International Islamic University Malaysia, 2012.