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Balckner, Lester A. | "Ray system" of underground mining | Ray Consolidated Copper Company; Copper mines and mining | 1915-02 | thesis |
1 - 25 of 1
| Author | Title | Subject | Date | Publication Type | ||
|---|---|---|---|---|---|---|
| 1 |
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Balckner, Lester A. | "Ray system" of underground mining | Ray Consolidated Copper Company; Copper mines and mining | 1915-02 | thesis |