I'm pretty sure that searching for create table expression against the 10gR2 documentation should return something, but it does not :
Please have a look from that url : http://www.oracle.com/pls/db102/homepage
I reported this problem just now via internal email. I am not 100% sure that I found the exact development group to report this to, but they can probably at least forward the message. When I tested the search on many terms, I got 0 results too.