Citazione Stile APA (7a Edizione)

Keefe, E. K. (1974). Area handbook for Bulgaria. For sale by the Supt. of Docs., U.S. Govt. Print. Off.].

Citazione stile Chigago Style (17a edizione)

Keefe, Eugene K. Area Handbook for Bulgaria. [Washington: For sale by the Supt. of Docs., U.S. Govt. Print. Off.], 1974.

Citatione MLA (8a ed.)

Keefe, Eugene K. Area Handbook for Bulgaria. For sale by the Supt. of Docs., U.S. Govt. Print. Off.], 1974.