| 其他書名 | A Draft Report to Congress as Required by Public Law 101-578 of November 15, 1990 |
| 出版 | National Park Service, U.S. Department of the Interior, Southwest Regional Office, 1994 |
| URL | http://books.google.com.hk/books?id=crYtNP0IUzQC&hl=&source=gbs_api |
| EBook | FULL_PUBLIC_DOMAIN |