AAPG Fallow ms, "Grabens on Anticlines in the Gulf Coastal Plain and Downthrown Thinning of the Sedimentary Section", 1972, Box: 55, Folder: 11. Hollis Hedberg papers, RH MS 546. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/150623 Accessed June 16, 2025.