1. BP Statistical Review of World Economy, June 2003.
2. G. Sachs, Dreaming with BRICS: the path to 2050, Global Economics Paper 99, October 2003.
3. Brace yourself for the end of oil, New Scientist, 2/8/2003, p. 9.
4. Into deeper water, The Economist, 8/12/2001, p. 17.
5. H. Rempel, Will the hydrocarbon area finish soon, DGMK/BGR Event, Hannover, 23/5/2000.