APA (7th ed.) Citation

Leonard, M., & Sale, J. (2013). Overview of the Louisiana Purchase. Encyclopedia Britannica.

Chicago Style (17th ed.) Citation

Leonard, Melinda, and Jennifer Sale. Overview of the Louisiana Purchase. Chicago, IL: Encyclopedia Britannica, 2013.

MLA (9th ed.) Citation

Leonard, Melinda, and Jennifer Sale. Overview of the Louisiana Purchase. Encyclopedia Britannica, 2013.