| Number | Name | Date | Kind |
|---|---|---|---|
| 449739 | Hazelton | Apr 1891 | |
| 1560174 | Gaisman | Nov 1925 | |
| 1981324 | Peterson | Nov 1934 | |
| 1984393 | Brown | Dec 1934 | |
| 2881613 | Taylor et al. | Apr 1959 | |
| 3597928 | Pilaar | Aug 1971 | |
| 4094380 | Kobayashi et al. | Jun 1978 | |
| 4834575 | Barth et al. | May 1989 | |
| 5496129 | Dube | Mar 1996 |
| Number | Date | Country |
|---|---|---|
| 14691 | Jun 1946 | CAX |
| Entry |
|---|
| McCauley Limited brochure, Rainstone 1 Block, 2 pages, 1992. |
| Borgwardt, Sonke, Concrete Precasting Plant and Technology, "Performance and Fields of Application for Permeable Paving Systems", Feb. 1997, pp. 100-105. |
| Uni-Group U.S.A., "The Environmentally Beneficial Paving System", Uni-Eco Stone brochure, 1993. |
| "Super Decor" interlocking paving stone, p. 11: Sweet's General Building and Renovation Catalog, vo. 3, 1993; Anchor Concrete Products Inc., Buyline 6518, 04200/ANC. |