APA (7th ed.) Citation

Whittington, H. B., & Evitt, W. R. (1953). Silicified Middle Ordovician trilobites. Geological Society of America.

Chicago Style (17th ed.) Citation

Whittington, H. B., and W. R. Evitt. Silicified Middle Ordovician Trilobites. [New York]: Geological Society of America, 1953.

MLA (8th ed.) Citation

Whittington, H. B., and W. R. Evitt. Silicified Middle Ordovician Trilobites. Geological Society of America, 1953.