International strategic minerals inventory summary report--rare-earth oxides
Wayne D. Jackson and Grey Christiansen.
- Washington U.S. G.P.O. 1993.
- vi, 68 p. ill., maps 27 cm.
- U.S. Geological Survey circular 930-N .
"Prepared as a cooperative effort among earth-science and mineral-resource agencies of Australia, Canada, the Federal Republic of Germany, the Republic of South Africa, the United Kingdom, and the United States of America."