| 其他書名 | And Coal-mine Statistics Supplementing Those Published in Bulletin 115, and a List of Permissible Explosives, Lamps, and Motors Tested Prior to January 31, 1921 |
| 出版 | U.S. Department of the Interior, Bureau of Mines, 1921 |
| URL | http://books.google.com.hk/books?id=Q8-fn8c16CIC&hl=&source=gbs_api |
| EBook | FULL_PUBLIC_DOMAIN |