Gaya APA

Levitt, S, D., Dubner, S, J. (2009). Freakonomics: A Rogue Economist Explores the Hidden Side of Everything . New York: HarperCollins.

Gaya MLA

Levitt, Steven, D.., Dubner, Stephen, J.. "Freakonomics: A Rogue Economist Explores the Hidden Side of Everything". New York: HarperCollins, 2009. Text.