California Code, Code of Civil Procedure - CCP § 97

(1) A person who, in his or her individual capacity, is a party to the litigation and who calls himself or herself as a witness.

(2) An adverse party.

(3) Witnesses and evidence used solely for purposes of impeachment.

(4) Documents obtained by discovery authorized by this chapter.

(5) The court may, upon such terms as may be just (including, but not limited to, continuing the trial for a reasonable period of time and awarding costs and litigation expenses), permit a party to call a witness or introduce evidence which is required to be, but is not included in such party's statement so long as the court finds that such party has made a good faith effort to comply with subdivision (c) of Section 96 or that the failure to comply was the result of his or her mistake, inadvertence, surprise or excusable neglect as provided in Section 473.