Article 13: Proceedings before the Court 1. Proceedings before the Court shall consist of two parts; written and oral. 2. Written proceedings shall consist of the application entered in the Court, notification of the application, the defence, the reply or counter-statement, the rejoinder and any other briefs or documents in support. 3. Documents comprising the written proceedings shall be addressed to the Chief Registrar of the Court in the order and within the time limit fixed by the Rules of Procedure of the Court. A copy of each document produced by one party shall be communicated to the other party. 4. The oral proceedings shall consist of the hearing of parties, agents witnesses, experts, advocates or counsels. Article 14: Sittings of the Court 1. The President shall issue summons to the parties to appear before the court. He shall determine the roll of the Court and preside over its sittings. 2. Sittings and deliberations of the Court shall be valid when the President and at least two judges are present, but such that any sitting of the Court shall comprise of an uneven number of its members. 3. Sittings of the Court shall be public. The Court may however, sit in camera at the request of one of the parties or for reasons which only the Court may determine. Article 15: Production of Documents 1. At any time, the Court may request the parties to produce any documents and provide any information or explanation which it may deem useful. Formal note shall be taken of any refusal. 2. The Court may also request a Member State which is not involved in the dispute or any Community Institution to make available any information which it deems necessary for the settlement of the dispute. Article 16: Enquiries and Expert Opinion The Court may, in any circumstance, and, in accordance with its Rules of Procedure, order any manner of judicial enquiry summon any person, organisation or institution to carry out an enquiry or give an expert opinion. Article 17: Examination of Witnesses 1. Witnesses upon whom a summon has been served must appear before the Court. They shall be heard under conditions specified in the Rules of Procedure of the Court.