APA (7e ed.) Bronvermelding

Kinghorn, J. R., Clauset, K., & Willis, C. L. (1979). A guide to four essential themes. Charles F. Kettering Foundation.

Chicago (17e ed.) Bronvermelding

Kinghorn, Jon Rye, Karl Clauset, en Charles L. Willis. A Guide to Four Essential Themes. Dayton, Ohio: Charles F. Kettering Foundation, 1979.

MLA (9e ed.) Bronvermelding

Kinghorn, Jon Rye, et al. A Guide to Four Essential Themes. Charles F. Kettering Foundation, 1979.