The sale of any property, real or personal, or of any interest therein, the value of which is more than ten thousand dollars ($10,000.00), shall be made only by authority of a special ordinance other than an emergency ordinance. Such ordinance shall be published in full in a newspaper of general circulation within the city within ten (10) days after its passage and shall include a section reading substantially as follows: “Section ______. This ordinance shall be referred to a vote of the electors of the city if a proper referendum petition is properly filed within thirty (30) days after its passage; otherwise it shall go into effect thirty (30) days after its passage.”