| Number | Name | Date | Kind |
|---|---|---|---|
| 3762191 | Smith | Oct 1973 | |
| 3831407 | Coleman | Aug 1974 | |
| 3837545 | Rogers, Jr. | Sep 1974 | |
| 4024738 | Pi | May 1977 | |
| 4063637 | Danforth | Dec 1977 | |
| 4438877 | Jackson | Mar 1984 | |
| 4766616 | Donahue | Aug 1988 | |
| 5619873 | Wood | Apr 1997 | |
| 5664444 | Schaan | Sep 1997 |
| Number | Date | Country |
|---|---|---|
| 2370622 | Jul 1978 | FRX |
| 7511168 | Mar 1977 | NLX |
| Entry |
|---|
| Popular Science, Doty, Wordless Workshop, p. 121, Nov. 1981. |