APA (7th ed.) Citation

MADDISON, A. (1989). The World economy in the 20th century. OECD.

Chicago Style (17th ed.) Citation

MADDISON, Angus. The World Economy in the 20th Century. Paris: OECD, 1989.

MLA (8th ed.) Citation

MADDISON, Angus. The World Economy in the 20th Century. OECD, 1989.