CA Civ Proc Code Section 1913

(a)

Subject to subdivision (b), the effect of a judicial record of a sister state is the same in this state as in the state where it was made, except that it can only be enforced in this state by an action or special proceeding.

(b)

The authority of a guardian, conservator, or committee, or of a personal representative, does not extend beyond the jurisdiction of the government under which that person was invested with authority, except to the extent expressly authorized by Article 4 (commencing with Section 2011) of Chapter 8 of Part 3 of Division 4 of the Probate Code or another statute.