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by Geological Survey
by Canada, Geological Survey of; Collins, William Henry
by U. S. Department of the Interior; U. s. Geological Survey
by Geological Survey of Georgia
by Survey, Kansas Geological
by Geological Survey (CON)
by Editor: Christopher C. Johnson (British Geological Survey); Editor: Alecos Demetriades; Editor: Juan Locutura; et al.
by U.S. Department of the Interior; U.S. Geological Survey