Gaya APA

Williamson, J., Milner, C. (1991). The World economy : a textbook in international economics (4th ed). New York: Harvester Wheatsheaf.

Gaya MLA

Williamson, John., Milner, Chris. "The World economy : a textbook in international economics". 4th ed New York: Harvester Wheatsheaf, 1991. Text.