[MSDN Library June 1998] Hookswitch Devices (70.429252782194%)

MSDN Library Visual Studio 6.0 > Platform SDK > Networking and Distributed Services > Telephony Application Programming Interface (TAPI) > TAPI Version 2.1 > Overviews > Phone Devices Overview

[MSDN Library June 1998] Hookswitch Devices (41.3056438791733%)

MSDN Library Visual Studio 6.0 > Platform SDK > Networking and Distributed Services > Telephony Application Programming Interface (TAPI) > TSPI Version 2.1 > Overviews > Phone Devices > Supplementary Phone Services