Section 3. Other Collective Bargaining Agreements. In addition to the Producers which are parties to the Writers' Guild- Industry Health Fund Trust Agreement, any employer who enters into or becomes bound by a WGA collective bargaining agreement, to which this Trust Agreement is annexed with the approval of the Trustees, may become a party to this Trust Agreement and contribute to the Health Fund pursuant to the terms hereof, upon the vote of three-fourths of the Trustees present and voting at a meeting of the Trustees at which a quorum is present. Any Trustee may require a unit vote in accordance with the provisions of Section 5 of Article VI.