by the United Nations Educational, Scientific and Cultural Organization

“ The contracting States undertake to give every possible facility to the importation of educational, scientific or cultural materials, which are imported exclusively for showing at a public exhibition approved by the competent authorities of the importing country and for subsequent re-exportation. These facilities shall include the granting of the necessary licences and exemption from customs duties and internal taxes and charges of all kinds payable on importation, other than fees and charges corresponding to the approximate cost of services rendered. ”