Geological Survey (U.S.) & Schruben, P. G. (1999). Geology and resource assessment of the Venezuelan Guayana Shield at 1:500,000 scale: A digital representation of maps published by the U.S. Geological Survey. U.S. Geological Survey.
Chicago Style (17th ed.) CitationGeological Survey (U.S.) and Paul G. Schruben. Geology and Resource Assessment of the Venezuelan Guayana Shield at 1:500,000 Scale: A Digital Representation of Maps Published by the U.S. Geological Survey. Reston, VA.: U.S. Geological Survey, 1999.
MLA (9th ed.) CitationGeological Survey (U.S.) and Paul G. Schruben. Geology and Resource Assessment of the Venezuelan Guayana Shield at 1:500,000 Scale: A Digital Representation of Maps Published by the U.S. Geological Survey. U.S. Geological Survey, 1999.
Warning: These citations may not always be 100% accurate.