The Economist. (1997). The World in 1997. U.S.A: The Economist.
Chicago Style aipamenaThe Economist. The World in 1997. U.S.A: The Economist, 1997.
MLA aipamenaThe Economist. The World in 1997. U.S.A: The Economist, 1997.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.