| Type |  Book |
| ชื่อเรื่อง | Coal mining cost models : final report / prepared by Energy Resources Group, NUS Corporation ; principal investigator, George W. Toth ; prepared for Electric Power Research Institute |
| พิมพลักษณ์ | Rockville, Md. : NUS Corp., 1977 |
| รูปเล่ม | 2 v. : ill. ; 28 cm |
| หัวเรื่อง | Coal mines and mining --Costs [] |
| | Coal mines and mining --Economic aspects [] |
| | Coal mines and mining --Equipment and supplies [] |