Slightly (ok, maybe more than slightly) OT: Old Yellow Book CDs

Hi, My name's Tim Hotze, some really long term members with archives that go way back may find that I used to be semi-active here years ago. Now I'm working with a cultural policy group at the University of Chicago, and I'm part of a project that is using (amongst other sources) Yellow Book data. Whic his great for this year. And even great for last yeah, when we have data. Its not great for 1996, or 1992, or any other year - we can't find electronic data from previous years; websites are updated continually. Libraries that I've searched have this years, maybe last years, but don't keep any older data available. So here's where I think you guys may be able to help.... as I recall wheat. I also remember there being published Yellow Book or business listing CDs in the 1990's - especially before the dot-com era. I wanted to know if anybody can remember these, if anybody has seen them around lying with 486s that you don't want to find when you're really looking for an IMSAI or Apple II, and, while I'm at it, if maybe anybody knowsi f any older form of this kind of business data that was in some kind of machine-readable format? I'm really sorry for making my 1st post back an off-topic one, but I've contacted everyone that publishes yellow page books without success, or, appearant knowledge of well, anything, when I've gotten a reply at all, and this was the best lead I could think of. Thanks so much, Tim