APA aipamena

Hedley, D. (1981). World energy: The facts and the future. New York: Facts on File.

Chicago Style aipamena

Hedley, Don. World Energy: The Facts and the Future. New York: Facts on File, 1981.

MLA aipamena

Hedley, Don. World Energy: The Facts and the Future. New York: Facts on File, 1981.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.