Article 42 (4)

Instruments of ratification, acceptance or approval of amendments to this Treaty shall be deposited with the Depositary. Amendments shall enter into force between Contracting Parties having ratified, accepted or approved them on the ninetieth day after deposit with the Depositary of instruments of ratification, acceptance or approval by at least threefourths of the Contracting Parties. Thereafter the amendments shall enter into force for any other Contracting Party on the ninetieth day after that Contracting Party deposits its instrument of ratification, acceptance or approval of the amendments.