| Number | Date | Country | Kind |
|---|---|---|---|
| 52807/89[U] | Jan 1989 | ITX |
| Number | Name | Date | Kind |
|---|---|---|---|
| D47324 | Guth | May 1915 | |
| D53152 | Irwin | Apr 1919 | |
| D87213 | Hoffmann | Jun 1932 | |
| 1772724 | Lazerson | Aug 1930 |
| Entry |
|---|
| Architectural Record, 4-1965, p. 167, "Acoustical Clouds", suspended triangular panels. |