APA (7th ed.) Citation

Ringo, J., & Massa, M. (2018). The valley of shadows. Baen.

Chicago Style (17th ed.) Citation

Ringo, John, and Mike Massa. The Valley of Shadows. Riverdale, NY: Baen, 2018.

MLA (8th ed.) Citation

Ringo, John, and Mike Massa. The Valley of Shadows. Baen, 2018.

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