"The U.S. Exclusive Economic Zone--A summary of its Geology, Exploration, and Resource Potential" Geological Survey Circular 912, Box: 31, Folder: 11. Hollis Hedberg papers, RH MS 546. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/149874 Accessed November 24, 2024.