APA aipamena

The Economist. (1997). The World in 1997. U.S.A: The Economist.

Chicago Style aipamena

The Economist. The World in 1997. U.S.A: The Economist, 1997.

MLA aipamena

The Economist. The World in 1997. U.S.A: The Economist, 1997.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.