where to find owners manuals

Any suggestions on where to look for older Nakamichi owners manuals, looking for CA5 preamp and PA7 power amp.
Any ideas appreciated.
Check out audiocircuit .com The owners manuals for the amp and preamp are available. You need to register to download the manuals. There is a wealth of info on the site and it is continually being updated. Hope this helps.
No guarantee, but try HiFiEngine.com
Thanks to all for the info, very helpful, got my manuals.