The easiest way to find CP sources is, if you have access to it, to use
the web. The address to use is:
http://randomaccess.unm.edu/www/cp/cparchive.html Once
there look at the commercial growers index (or whatever it's called) nad
there you'll find a list of all the growers and what each one has to
offer. You'll also find CP publications index (or whatever it's called)
which you can download. It lists all the major CP publications to date.
You could also go to your friendly neighborhood library; they may have
some books on CP's.
HTH
Ben