News selected on topics and regions – oil and gas, business, politics, IT, the South Caucasus, the Caspian Sea region, Central Asia Ranking of the Azerbaijani banking sector The Turkish Supreme Board of Election has announced that a constitutional referendum will be held on April 16, Reuters reported. The referendum will propose an 18-article amendment to the Turkish Constitution that has been long sought by the ruling Justice and Development Party and its founder, President Recep Tayyip Erdogan.