Labels:text | map | world OCR: Ranking of the World's Oil and Gas Provinces by Known Petroleum Volumes by T. R. Klett, T. S. Ahlbrandt, J. W. Schmoker, and G. L. Dolton U.S. Department of the Interior U.S. Geological Survey U.S. Geological Survey USGS Open File Report 97-463 1997 science for a changing world
