Experimental Adit in the Chattanooga Shale, report, March 1949; (https://digital.library.unt.edu/ark:/67531/metadc1050733/m1/5/: accessed July 17, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .
Experimental Adit in the Chattanooga Shale, report, March 1949; (https://digital.library.unt.edu/ark:/67531/metadc1050733/m1/5/: accessed July 17, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .