| Number | Date | Country | Kind |
|---|---|---|---|
| 2045691 | Feb 1995 | GBX | |
| 2045692 | Feb 1995 | GBX |
| Entry |
|---|
| Graingn's Spring '86 Cat., p. 1195, Unvented Gas Heater a, top of page. |
| The National Energy Journal Jan. 1984, p. 9, Unvented Gas Leatas B and C, Middle and Right Side of Page WHA Tradeshow Brochures. |