APA (7th ed.) Citation

U.S. Coast and Geodetic Survey. (1919). Results of observations made at U.S. Coast and Geodetic Survey magnetic observatory near Tucson, Ariz. in 1919 and 1920. GPO.

Chicago Style (17th ed.) Citation

U.S. Coast and Geodetic Survey. Results of Observations Made at U.S. Coast and Geodetic Survey Magnetic Observatory Near Tucson, Ariz. in 1919 and 1920. [Washington]: GPO, 1919.

MLA (9th ed.) Citation

U.S. Coast and Geodetic Survey. Results of Observations Made at U.S. Coast and Geodetic Survey Magnetic Observatory Near Tucson, Ariz. in 1919 and 1920. GPO, 1919.