claim: Mikhail Prokhorov is the former chairman of Russia's largest silver producer.
evidence: The Serbian Volleyball League -LRB- srb.  : Одбојкашко првенство Србије -RRB- is the highest level of men 's volleyball in Serbia and it is organized by Serbian Volleyball Federation .. volleyball. volleyball. Serbia. Serbia. It often refer as Wiener Stadtische Liga , named after the main sponsor of the league , Wiener Stadtische .. Wiener Stadtische. Vienna Insurance Group. Serbia Volleyball League is currently contested by 10 clubs .. Serbia. Serbia