Also available online in PDF format from the U.S. Geological Survey Warehouse (http://pubs.er.usgs.gov/).
"Prepared in cooperation with the Ministerio de Fomento, Instituo Geológico del Perú, under the auspices of the Interdepartmental Committee on Scientific and Cultural Cooperation, Department of State."
Bibliography
Includes bibliographical references (pages 42-43) and index.