APA (7th ed.) Citation

Heigold, P. C., & Ringler, R. W. (1979). A seismic refraction survey of the lower Illinois Valley bottomlands. Illinois State Geological Survey.

Chicago Style (17th ed.) Citation

Heigold, Paul C., and Robert W. Ringler. A Seismic Refraction Survey of the Lower Illinois Valley Bottomlands. Urbana: Illinois State Geological Survey, 1979.

MLA (9th ed.) Citation

Heigold, Paul C., and Robert W. Ringler. A Seismic Refraction Survey of the Lower Illinois Valley Bottomlands. Illinois State Geological Survey, 1979.