California Code, Government Code - GOV § 8188

The judgment shall determine the validity or invalidity respectively of the matters specified in Section 8187.  The judgment shall be subject to being reopened under Section 473 or 473.5 of the Code of Civil Procedure, or otherwise only within 90 days after the entry of the judgment, and the petitioner and any person who has appeared in the special proceeding may move for a new trial under proper circumstances and upon appropriate grounds and may appeal from the judgment.