Esmael Ahmed, Tsegay Girmay, & Longdom Publishing. Psychoactive Substances Use (Khat, Alcohol and Tobacco) and Associated Factors among Debre Markos University Students, North-West Ethiopia, 2013.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Esmael Ahmed, Tsegay Girmay, و Longdom Publishing. Psychoactive Substances Use (Khat, Alcohol and Tobacco) and Associated Factors Among Debre Markos University Students, North-West Ethiopia, 2013.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Esmael Ahmed, et al. Psychoactive Substances Use (Khat, Alcohol and Tobacco) and Associated Factors Among Debre Markos University Students, North-West Ethiopia, 2013.
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