Number | Date | Country | Kind |
---|---|---|---|
2750555 | Nov 1977 | DEX |
Number | Name | Date | Kind |
---|---|---|---|
3076010 | Beck et al. | Jan 1963 | |
3297796 | Smith et al. | Jan 1967 | |
4060571 | Kapps et al. | Nov 1977 |
Entry |
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Nachod et al., "Ion Exchange Technology", Academic Press Inc., N.Y., (1956), p. 12. |