APA (7th ed.) Citation

Willis, S. (2011). Hearts of Oak trilogy (1. publ. in Great Britain.). Querus.

Chicago Style (17th ed.) Citation

Willis, Sam. Hearts of Oak Trilogy. 1. publ. in Great Britain. London: Querus, 2011.

MLA (9th ed.) Citation

Willis, Sam. Hearts of Oak Trilogy. 1. publ. in Great Britain. Querus, 2011.