Number | Name | Date | Kind |
---|---|---|---|
3373653 | Roberts et al. | Mar 1968 | |
3378831 | Metcalf | Apr 1968 | |
3562491 | Branfield | Feb 1971 | |
3940210 | Donohue | Feb 1976 | |
3989371 | Valentine | Nov 1976 | |
3989930 | Sohm | Nov 1976 | |
4026642 | Tanaka et al. | May 1977 | |
4054380 | Donohue et al. | Oct 1977 |
Entry |
---|
Guido, A. A., "Preventing Copying of Classified Information", IBM Technical Disclosure Bulletin, vol. 19, No. 4, Sep. 1976, pp. 1469 and 1470. |