Leventhal, Joel S., author.
[Reston, Va.] : Department of the Interior, U.S. Geological Survey ; Denver, CO : For sale by the Books and Open-File Reports Section, U.S. Geological Survey, 1989.
1989
International Geological Correlation Programme. Project 254. United States Working Group.
Washington : Dept. of the Interior, U.S. Geological Survey : Free on application to the Books and Open-File Services Section, U.S. Geological Survey, 1989.
1989