Assorted letters to international groups. Badri, Omar; General Secretary of OPLC (see OPEC), 1962 - 1975, Box: 4, Folder: 40. Charles Heller papers, RH MS 314. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/489267 Accessed November 28, 2024.