"Prepared in cooperation with the Universidad Nacional de Mexico, Instituto de Geologia and Secretaria de la Economia Nacional Direccion General de Minas Y Petoleo under the auspices of the Interdepartmental committee on Cultural and Scientific Cooperation, Department of State."
Title from title screen (viewed July 10, 2014).
Also available online in PDF format from the U.S. Geological Survey Warehouse (http://pubs.er.usgs.gov/).