APA (7th ed.) Citation

Heigold, P. C. (1970). A gravity survey of extreme southeastern Illinois. Illinois State Geological Survey.

Chicago Style (17th ed.) Citation

Heigold, Paul C. A Gravity Survey of Extreme Southeastern Illinois. Urbana: Illinois State Geological Survey, 1970.

MLA (9th ed.) Citation

Heigold, Paul C. A Gravity Survey of Extreme Southeastern Illinois. Illinois State Geological Survey, 1970.

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