| Keptel, Inc., brochure for the SNI.RTM.-4600 Network Interface System, Feb. 1988. |
| Keptel, Inc., brochure for the SNI.RTM.-4600 Network Interface System, Oct. 1991. |
| GTE Products Corporation, brochure for the Sylvania Control Devices CP-765 Network Interface Device, printed Jun. 1987. |
| GTE Products Corporation, brochure for the Sylvania Control Devices CP-761 Network Interface Device, printed Sep. 1989. |
| Keptel brochure, "The Only Network Interface You'll Ever Use," Keptel, Ocean, New Jersey. |
| Siecor brochure, "Siecor Introduces New Multiline NID Solutions", Siecor Corp., Hickory, N.C. |
| Keptel brochure, "SNI-5000, Tomorrow's Network Interface System Today", Keptel Inc., 1985. |
| GTE brochure, "Weatherproof, Corrosion Proof . . . and We Guarantee It", Sylvania GTE Control Devices, Dec. 1984. |
| Lippincott brochure, "GL-700 Multi-Unit Network Interface Device", Lippincott Industries, Spokane, Washington, May 1988. |
| Lippincott advertisement, vol. 211, Telephony, Sep. 9, 1986. |
| GTE brochure, Protected Terminating Device NI-2006, GTE Control Devices, Standish, Me., May 1992. |
| GTE brochure, Protected Terminating Device PTD, GTE Control Devices, Standish, Me., May 1992. |
| GTE brochure, Protected Terminating Devices NI-2025, NI-2050, NI-2100, NI-2200, GTE Control Devices, Standish, Me., May 1992. |
| GTE brochure, Introducing the Next Step In the Evolution of Network Interface Technology, GTE Control Devices, Standish, Me., May 1992. |