| Number | Name | Date | Kind |
|---|---|---|---|
| 2162584 | Kole | Jun 1939 | |
| 3570139 | Ladd | Mar 1971 | |
| 4011311 | Noomen | Mar 1977 | |
| 4051159 | Tsoucalas | Sep 1977 |
| Number | Date | Country |
|---|---|---|
| 163659 | Dec 1981 | JPX |
| 1223220 | Feb 1971 | GBX |
| Entry |
|---|
| E. Faber Co. 1901 catalog, "Triangle" Pencils, p. 12 only. |
| Milton Bradley 1965-66 catalog, pp. 2, 3, 9 only. |