Style de citation APA (7e éd.)

Keefe, E. K. (1974). Area handbook for Bulgaria. U.S. Government Printing Office.

Style de citation Chicago (17e éd.)

Keefe, Eugene K. Area Handbook for Bulgaria. Washington, D.C: U.S. Government Printing Office, 1974.

Style de citation MLA (9e éd.)

Keefe, Eugene K. Area Handbook for Bulgaria. U.S. Government Printing Office, 1974.