APA-referens (7:e uppl.)

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.

Chicago-referens (17:e uppl.)

Esmael Ahmed, Tsegay Girmay, och Longdom Publishing. Psychoactive Substances Use (Khat, Alcohol and Tobacco) and Associated Factors Among Debre Markos University Students, North-West Ethiopia, 2013.

MLA-referens (9:e uppl.)

Esmael Ahmed, et al. Psychoactive Substances Use (Khat, Alcohol and Tobacco) and Associated Factors Among Debre Markos University Students, North-West Ethiopia, 2013.

Varning: dessa hänvisningar är inte alltid fullständigt riktiga.