Lieberman, L. (1992). Preparation for the CLEP, College-Level Examination Program: The 5 general examinations (3rd ed.). Arco : Prentice Hall.
Chicago-referens (17:e uppl.)Lieberman, Leo. Preparation for the CLEP, College-Level Examination Program: The 5 General Examinations. 3rd ed. New York: Arco : Prentice Hall, 1992.
MLA-referens (9:e uppl.)Lieberman, Leo. Preparation for the CLEP, College-Level Examination Program: The 5 General Examinations. 3rd ed. Arco : Prentice Hall, 1992.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.