APA (7th ed.) Citation

Ritchie, D. A. (2010). The U.S. Congress: A very short introduction. Oxford University Press.

Chicago Style (17th ed.) Citation

Ritchie, Donald A. The U.S. Congress: A Very Short Introduction. Oxford [etc.]: Oxford University Press, 2010.

MLA (9th ed.) Citation

Ritchie, Donald A. The U.S. Congress: A Very Short Introduction. Oxford University Press, 2010.