A complete answer to this question depends on where you live. IF you are in a city with a federal court library or, lucky you, in a city where a Ninth Circuit Court of Appeals Library is located, you may have a few other options.
You may also have access to the U.S. Court of Appeals for the Ninth Circuit (official name) briefs that are available on Westlaw or Lexis.
In time the briefs may appear on PACER (and a few may be there now, but I’ve not ever seen one there myself).