Number | Name | Date | Kind |
---|---|---|---|
333927 | Currier | Jan 1886 | A |
4624197 | Drake | Nov 1986 | A |
4702323 | Smit et al. | Oct 1987 | A |
5255617 | Williams et al. | Oct 1993 | A |
5524711 | Harris | Jun 1996 | A |
5590721 | Van Mill | Jan 1997 | A |
Number | Date | Country |
---|---|---|
2079572 | Jan 1982 | GB |
Entry |
---|
Pfost, “Ridge-Till Tips”, University of Missouri Extension, Agricultural Publication G1652, Oct. 1993. |