APA aipamena

National Geographic Society. (2000). Forces. New York: McGraw-Hill School Division.

Chicago Style aipamena

National Geographic Society. Forces. New York: McGraw-Hill School Division, 2000.

MLA aipamena

National Geographic Society. Forces. New York: McGraw-Hill School Division, 2000.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.