APA (7th ed.) Citation

Frye, J. C., Glass, H. D., Kempton, J. P., & Willman, H. B. (1969). Glacial tills of northwestern Illinois. State of Illinois, Department of Registration and Education.

Chicago Style (17th ed.) Citation

Frye, John Chapman, Herbert D. Glass, John P. Kempton, and Harold B. Willman. Glacial Tills of Northwestern Illinois. Urbana: State of Illinois, Department of Registration and Education, 1969.

MLA (9th ed.) Citation

Frye, John Chapman, et al. Glacial Tills of Northwestern Illinois. State of Illinois, Department of Registration and Education, 1969.