| 其他書名 | Coal, Phosphate, Potash, Sodium, and Other Mineral Production, Royalty Income, and Related Statistics, 1920 Through 1972, Fiscal Year 1972 |
| 出版 | U.S. Geological Survey, Conservation Division, 1973 |
| URL | http://books.google.com.hk/books?id=uGpBsNJsU2IC&hl=&source=gbs_api |
| EBook | FULL_PUBLIC_DOMAIN |