Grout, F. F., & Soper, E. K. (1919). Clays and shales of Minnesota. Department of the Interior, United States Geological Survey.
Chicago Style (17th ed.) CitationGrout, Frank F., and Edgar Kirke Soper. Clays and Shales of Minnesota. [Washington, D.C.]: Department of the Interior, United States Geological Survey, 1919.
MLA (9th ed.) CitationGrout, Frank F., and Edgar Kirke Soper. Clays and Shales of Minnesota. Department of the Interior, United States Geological Survey, 1919.
Warning: These citations may not always be 100% accurate.