cosponsored by U.S. Geological Survey, Agricultural Research Service, Soil Conservation Serivce, Reston, Virginia, February 5-8, 1990 ; compiled by Madge Ertel
sponsored by Section E (Geology and Geography) of the Pacific Division, American Association for the Advancement of Science, the School of Mines and Earth Sciences, University of Idaho, and the Idaho Bureau of Mines and Geology on the occasion of the 100th anniversary of the founding of the United States Geological Survey ; edited by Alan E. Leviton ... [and others]