| Number | Name | Date | Kind |
|---|---|---|---|
| 543961 | Hayward | Aug 1895 | |
| 693511 | Garrett et al. | Feb 1902 | |
| 1420283 | Randlett | Jun 1922 | |
| 2102310 | Egan | Dec 1937 | |
| 3086655 | Compton | Apr 1965 | |
| 3472030 | Rieke | Oct 1969 | |
| 3587239 | Feland | Jun 1971 | |
| 4042506 | Wilson | Aug 1977 |
| Number | Date | Country |
|---|---|---|
| 2711141 | Sep 1978 | DEX |
| 60949 | Nov 1936 | NOX |
| 435872 | Oct 1935 | GBX |
| 1588677 | Apr 1981 | GBX |
| Entry |
|---|
| "California Culvert Practice", California Highways and Public Works, 1943, pp. 12-21. |