APA (7th ed.) Citation

Northup, S., Gates, H. L., Jr, Berlin, I., & McQueen, S. (2013). Twelve years a slave. Penguin Books.

Chicago Style (17th ed.) Citation

Northup, Solomon, Henry Louis Gates, Jr, Ira Berlin, and Steve McQueen. Twelve Years a Slave. New York, NY: Penguin Books, 2013.

MLA (8th ed.) Citation

Northup, Solomon, et al. Twelve Years a Slave. Penguin Books, 2013.

Warning: These citations may not always be 100% accurate.