APA (7th ed.) Citation

Willman, H. B. (1975). Handbook of Illinois stratigraphy. Illinois State Geological Survey.

Chicago Style (17th ed.) Citation

Willman, H. B. Handbook of Illinois Stratigraphy. Urbana: Illinois State Geological Survey, 1975.

MLA (9th ed.) Citation

Willman, H. B. Handbook of Illinois Stratigraphy. Illinois State Geological Survey, 1975.

Warning: These citations may not always be 100% accurate.