1. World Energy Supplies 1968–1972 Statistical Papers Series J No.17, United Nations 1974. Copies can be obtained from HMSO, London
2. Parker, A. World Power Conference Survey of Energy Resources, 1962, World Energy Conference, London
3. Parker, A. World Power Conference Survey of Energy Resources, 1968, World Energy Conference, London
4. World Energy Conference Survey of Energy Resources, 1974, The United States National Committee of the World Energy Conference, New York, N.Y. 10017. Copies can be obtained from the Central Office of the World Energy Conference, London
5. Albers, J. P. et al, Summary Petroleum and Selected Mineral Statistics for 120 Countries, including Offshore Areas, Geological Survey Professional Paper 817, U.S. Dept. of the Interior. Government Printing Office, Washington D.C. 1973