| Number | Name | Date | Kind |
|---|---|---|---|
| 4030555 | Boyce et al. | Jun 1977 | |
| 4272649 | Pfeiffer | Jun 1981 | |
| 4354680 | Kmiec | Oct 1982 | |
| 4542905 | Hooker | Sep 1985 | |
| 4620706 | Ijidakinro | Nov 1986 | |
| 4763256 | DeMar | Aug 1988 | |
| 4773646 | Joos, Jr. et al. | Sep 1988 | |
| 4840375 | Lawlor et al. | Jun 1989 | |
| 4934699 | Kaminkow et al. | Jun 1990 |
| Entry |
|---|
| "Popular Science" article, Aug. 1980, pp. 54-58, 116. |