| Number | Name | Date | Kind |
|---|---|---|---|
| 3594935 | Blattstein | Jul 1971 | |
| 3999050 | Pitroda | Dec 1976 | |
| 4162610 | Levine | Jul 1979 | |
| 4247927 | Oooka et al. | Jan 1981 | |
| 4270192 | Kudo | May 1981 | |
| 4353178 | Meezawa | Oct 1982 | |
| 4428681 | Icashio | Jan 1984 | |
| 4591840 | Curtis et al. | May 1986 |
| Number | Date | Country |
|---|---|---|
| 0005661 | May 1979 | EPX |
| 84102530 | Nov 1984 | EPX |
| 2537400 | Feb 1977 | DEX |
| 2904664 | Aug 1980 | DEX |
| 2026736 | Feb 1980 | GBX |
| Entry |
|---|
| Keith Clark Inc. Catalogue, Work-A-Day 1972 Calendars, face page and pp. 2 & 6. |
| IBM Bulletin, vol. 19, No. 7, Dec. 1976. |
| IBM Bulletin, vol. 26, Nov. 1, 1984. |