There have been many versions of the Constitution in Serbia with the most recent one being made on September 30, 2006. The Constitution can be amended by at least two-thirds of the National Assembly (the name of the parliament in Serbia) after being proposed by at least one-third of the National Assembly, the President of the Republic, or by a petition of at least 150,000 voters.  Some issues also must have a referendum which means that a majority (over 50%) of the people of the country have to vote for it.