Seminar, UN headquarters, New York - "Dates and statistics on world petroleum, production, consumption, and move by sea, 1890-1960", 1962, Box: 23, Folder: 29. Charles Heller papers, RH MS 314. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/493224 Accessed May 05, 2024.