Gaya APA

Levitt, S, D, D, S, J. (2009). Freakonomics: A Rogue Economist Explores The Hidden Side of Everything . New York: Herper Economics.

Gaya MLA

Levitt, Stevent, D, Dubner,, Stephen, J. "Freakonomics: A Rogue Economist Explores The Hidden Side of Everything". New York: Herper Economics, 2009. Text.