Initiative petitions proposing amendments to the constitution shall be signed by eight percent of the legal voters in each of two-thirds of the congressional districts in the state, and petitions proposing laws shall be signed by five percent of such voters. Every such petition shall be filed with the secretary of state not less than six months before the election and shall contain an enacting clause and the full text of the measure. Petitions for constitutional amendments shall not contain more than one amended and revised article of this constitution, or one new article which shall not contain more than one subject and matters properly connected therewith, and the enacting clause thereof shall be “Be it resolved by the people of the state of Missouri that the Constitution be amended:”. Petitions for laws shall contain not more than one subject which shall be expressed clearly in the title, and the enacting clause thereof shall be “Be it enacted by the people of the state of Missouri:”.