APA (7th ed.) Citation

Gutenberg, B., & Richter, C. (1941). Seismicity of the earth. The Society.

Chicago Style (17th ed.) Citation

Gutenberg, Beno, and Charles Richter. Seismicity of the Earth. [New York]: The Society, 1941.

MLA (9th ed.) Citation

Gutenberg, Beno, and Charles Richter. Seismicity of the Earth. The Society, 1941.