National Research Council (U.S.) Committee on State Geological Surveys. (1932). Summary information on the State Geological Surveys and the United States Geological Survey. Published by the National Research Council of the National Academy of Sciences.
Chicago-Zitierstil (17. Ausg.)National Research Council (U.S.) Committee on State Geological Surveys. Summary Information on the State Geological Surveys and the United States Geological Survey. Washington, D.C: Published by the National Research Council of the National Academy of Sciences, 1932.
MLA-Zitierstil (9. Ausg.)National Research Council (U.S.) Committee on State Geological Surveys. Summary Information on the State Geological Surveys and the United States Geological Survey. Published by the National Research Council of the National Academy of Sciences, 1932.