APA (7th ed.) Citation

Carpenter, E. J., & Cosby, S. W. (1939). Contra Costa County, California. Superintendent of Documents.

Chicago Style (17th ed.) Citation

Carpenter, E. J., and S. W. Cosby. Contra Costa County, California. Washington, D.C.: Superintendent of Documents, 1939.

MLA (9th ed.) Citation

Carpenter, E. J., and S. W. Cosby. Contra Costa County, California. Superintendent of Documents, 1939.