Number | Date | Country | Kind |
---|---|---|---|
2409754 | Mar 1974 | DT | |
2437203 | Aug 1974 | DT | |
2438130 | Aug 1974 | DT |
Number | Name | Date | Kind |
---|---|---|---|
3507951 | Morecroft et al. | Apr 1970 | |
3640674 | Berrie et al. | Feb 1972 | |
3725383 | Austin et al. | Apr 1973 | |
3817975 | Berrie et al. | Jun 1974 |
Entry |
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Modern Plastics Encyclopedia, for 1963 (vol. 40, No. 1A), Sept. 1962, p. 496. |