APA (7th ed.) Citation

Doyle, F. L. (1965). Geology of the Freeport quadrangle, Illinois. Illinois State Geological Survey.

Chicago Style (17th ed.) Citation

Doyle, F. L. Geology of the Freeport Quadrangle, Illinois. Urbana, Ill: Illinois State Geological Survey, 1965.

MLA (9th ed.) Citation

Doyle, F. L. Geology of the Freeport Quadrangle, Illinois. Illinois State Geological Survey, 1965.

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