1. The arbitral tribunal may decide which documents, exhibits or other evidence the parties should produce. The arbitral tri- bunal may reject any request, unless made by all parties, to establish a procedure whereby each party can request another party to produce documents.

2. Unless otherwise directed by the arbitral tribunal, state- ments by witnesses, including expert witnesses, shall be pre- sented in writing and signed by them.

3. The arbitral tribunal may decide which witnesses, includ- ing expert witnesses, shall testify to the arbitral tribunal if hear- ings are held.