18. Pet. Pros. of the Deep Offshore. File on Maps of Figs. 2 and 3 and on revisions, November 1978, Box: 83, Folder: 13. Hollis Hedberg papers, RH MS 546. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/151409 Accessed November 24, 2024.