APA (7th ed.) Citation
Chapman, S., & Bartels, J. (1940). Geomagnetism. Clarendon Pr.
Chicago Style (17th ed.) Citation
Chapman, Sydney, and Julius Bartels. Geomagnetism. Oxford: Clarendon Pr, 1940.
MLA (9th ed.) Citation
Chapman, Sydney, and Julius Bartels. Geomagnetism. Clarendon Pr, 1940.
Warning: These citations may not always be 100% accurate.