Number | Name | Date | Kind |
---|---|---|---|
2206922 | Smith | Jul 1940 | |
3302706 | Thompson et al. | Feb 1967 | |
3384416 | Ruehl et al. | May 1968 | |
3650564 | Williamson | Mar 1972 | |
3814480 | Dahl et al. | Jun 1974 | |
3934649 | Pasini et al. | Jan 1976 |
Number | Date | Country |
---|---|---|
1273469 | Jul 1968 | DEX |
1342998 | Jan 1974 | GBX |
Entry |
---|
"Degasifying Before Mining," Coal Age, Aug. 1961, pp. 74-78. |