APA (7th ed.) Citation

Grout, F. F., Sharp, R. P., & Schwartz, G. M. (1959). Bulletin No. 39. The Geology of Cook County Minnesota. Minnesota Geological Survey.

Chicago Style (17th ed.) Citation

Grout, Frank F., Robert P. Sharp, and George M. Schwartz. Bulletin No. 39. The Geology of Cook County Minnesota. Minnesota Geological Survey, 1959.

MLA (9th ed.) Citation

Grout, Frank F., et al. Bulletin No. 39. The Geology of Cook County Minnesota. Minnesota Geological Survey, 1959.