That's what I was worried about, you have to go to the company/publisher and ask for the sheets?
I meant that for them to be available online, somebody would have to obtain the obtain the IP rights to sell the sheet music. It's unreasonably difficult to do this, in most cases.
On the other hand, many beginner and intermediate instrumental books are collections of popular showtunes, tv, and movie themes... there could be loopholes about publishing sheet music, depending on the length of the excerpted music, instrumentation, or a certain amount of modification from the original notes.
Your best bet is probably to pay some upper-level jazz or composition major at your local university a few bucks to transcribe stuff for your personal usage. Musicians will do anything for money!