National Research Council (U.S.). Committee on State Geological Surveys, ebrary, Inc, & Leighton, M. M. (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.
Citazione stile Chigago Style (17a edizione)National Research Council (U.S.). Committee on State Geological Surveys, Inc ebrary, e Morris M. Leighton. 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.
Citatione MLA (9a ed.)National Research Council (U.S.). Committee on State Geological Surveys, et al. 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.