The persons concerned shall keep the documents referred to in Article 14 for the purposes of control by the customs authorities, for the period laid down in the provisions in force and for at least three calendar years, irrespective of the medium used. That period shall run from the end of the year in which: a) in the case of goods released for free circulation in circumstances other than those referred to in (b) or goods declared for export, from the end of the year in which the declarations for release for free circulation or export are accepted ...
