iv, 177-233 pages : illustrations, maps (part folded in pocket) ; 24 cm
OCLC
ocm06990501
Prepared in cooperation with the Universidad Nacional Autonoma de Mexico, Instituto de Geologia and Secretaria de la Economia Nacional Direccion General de Minas y Petroleo under the auspices of the Interdepartmental Committee on Scientific and Cultural Cooperation, Department of State.