APA (7th ed.) Citation

Thompson, Dennis, Pegler, & Gilliland. (2013). US combat shotguns. Osprey Publishing.

Chicago Style (17th ed.) Citation

Thompson, Dennis, Pegler, and Gilliland. US Combat Shotguns. Oxford: Osprey Publishing, 2013.

MLA (8th ed.) Citation

Thompson, et al. US Combat Shotguns. Osprey Publishing, 2013.