Number | Name | Date | Kind |
---|---|---|---|
3373440 | Jenkins et al. | Mar 1968 | |
4589140 | Bishop et al. | May 1986 | |
4692943 | Pietzsch et al. | Sep 1987 | |
4710946 | Hinch et al. | Dec 1987 | |
4764969 | Ohtomabe et al. | Aug 1988 |
Entry |
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"Continuous Wireless Core Drilling: An Alternative Method for Oil and Gas Exploration"; R. E. Swayne; Drill Bits; pp. 7-12; Spring 1988 (no dates). |