"World Tanker Outlook: Tanker supply and tanker demand", 1972; "Energy, money and ships", 1975 by Melvin A. Conant; "Average freight rate assessment;" and "Estimated international flow of petroleum and tanker utilization, 1968-1969" papers by P. H. Frankel, W. L. Newton, and Harold Hartley, Box: 20, Folder: 42. Charles Heller papers, RH MS 314. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/492952 Accessed May 16, 2024.