Code of Civil Procedure Article 346

Where a document identified to be introduced as documentary evidence is in a third person's possession, a party may move the court either to order such third person to produce such document or to designate a period of time within which the party who intends to introduce it as evidence shall produce such document.The provisions of the second paragraph and the third paragraph of Article 342 shall apply mutatis mutandis to the motion provided in the preceding paragraph.A preliminary showing shall be made with regard to the fact that the document is in a third person's possession and the reason why the third person has the duty to produce such document.