Areal Geology of the Illinois Fluorspar District by James C. Bradbury, James Watson Baxter, Carl Buckner Rexroad, David Lloyd Stevenson, Thomas Charles Buschbach, David Henry Swann, Donald Lee Graf, Lester Leroy Whiting, Orin Wainwright Rees, Paul Edwin Potter, Ralph Eugene Hunter, Richard Charles Anderson, Wayne Franklin Meents, Willis L. Busch, Charles William Collinson, Elwood Atherton, George A. Desborough, Irving Friedman, Jerry Alvin Lineback, Eugene Frund