Number | Date | Country | Kind |
---|---|---|---|
4129943 | Sep 1991 | DEX |
Number | Name | Date | Kind |
---|---|---|---|
2890257 | Ayers et al. | Jun 1959 | |
3378418 | Lissant | Apr 1968 | |
3416320 | Asher | Dec 1968 |
Entry |
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Database WPI, Section Ch, Week 7636, Derwent Publications Ltd., Abstract of JP-A-50 051 506, Class E 10, AN 76-67497X. |