Article XV. Initiative, Referendum and Amendment. Section 9. No convention shall be called by the Council to propose a new Constitution, unless the law providing for such convention shall first be approved by the People on a referendum vote at a regular or special election. Any amendments, alterations, revisions or new Constitution, proposed by such convention, shall be submitted to the registered voters of the Cherokee Nation at a general or special election and be approved by a majority of the registered voters voting thereon before the same shall become effective. The question of such proposed convention shall be submitted to the citizens of the Cherokee Nation at least once every twenty (20) years.