| Number | Name | Date | Kind |
|---|---|---|---|
| 2731680 | Bolt | Jan 1956 | |
| 3236400 | Turturro | Feb 1966 | |
| 3616592 | Rothman | Nov 1971 | |
| 3683571 | Walz | Aug 1972 | |
| 3805365 | Ashby | Apr 1974 | |
| 3884494 | Ashby | May 1975 |
| Number | Date | Country |
|---|---|---|
| 1,415,722 | Sep 1965 | FRX |
| 2,309,509 | Sep 1973 | DEX |
| 301,544 | Apr 1968 | SEX |
| Entry |
|---|
| The New Building Block by Center for Housing & Environmental Studies, Cornell Univ., 1968, p. 224. |
| Industrial Building by Diomant, published by Hiffe Books Ltd., London, vol. 1, p. 67, vol. 3, 91 na 640005, 1968. |
| Excavating Engineer, Jul. 1949, pp. 14, 15, 46, 47, 48. |