United Kingdom - "Petroleum industry" by P. B. Baxendell and coverage by The Economist, survey 5, July 26, 1975, Box: 14, Folder: 46. Charles Heller papers, RH MS 314. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/490236 Accessed April 28, 2024.