Number | Name | Date | Kind |
---|---|---|---|
D237999 | Runyon | Dec 1975 | |
4058794 | Menke | Nov 1977 |
Entry |
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Signal-Stat Dual-Comm Light/Sound System Catalog, 1975, p. 2, Federal Sign & Signal Corp., "Twin Sonic", System. |
Signal-Stat Dual-Comm Light/Sound System Catalog, 1975, p. 2, "Dual-Comm" System. |