"Stratigraphy of the Rio Querecual Section of Northeastern Venezuela" Hollis D. Hedberg, Geological Society of America Bulletin, v. 48, pp. 1971-2024, December 1, 1937, Box: 10, Folder: 36. Hollis Hedberg papers, RH MS 546. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/149258 Accessed May 23, 2024.