"Trade-marks of Yesterday’s Glaciers," pp. 350-355, 'Natural History' (October 1948). Ohio River formation, p. 354., 1948

"Trade-marks of Yesterday’s Glaciers," pp. 350-355, 'Natural History' (October 1948). Ohio River formation, p. 354., 1948, Box: 6, Folder: 21. Roy Bird Cook (1886-1961), Collector, Papers, A&M 1561. West Virginia and Regional History Center. https://archives.lib.wvu.edu/repositories/2/archival_objects/50757 Accessed December 19, 2024.