توثيق جمعية علم النفس الأمريكية APA (الطبعة السابعة)

Library of Congress. Federal Research Division & Metz, H. C. (1992). Sudan: A country study (4th ed.). Federal Research Division, Library of Congress : For sale by the Supt. of Docs., U.S. G.P.O..

توثيق أسلوب شيكاغو (الطبعة السابعة عشر)

Library of Congress. Federal Research Division و Helen Chapin Metz. Sudan: A Country Study. 4th ed. Washington, D.C.: Federal Research Division, Library of Congress : For sale by the Supt. of Docs., U.S. G.P.O., 1992.

توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)

Library of Congress. Federal Research Division و Helen Chapin Metz. Sudan: A Country Study. 4th ed. Federal Research Division, Library of Congress : For sale by the Supt. of Docs., U.S. G.P.O., 1992.