6.Producers making direct sales shall keep available for the competent authority of the Member State, for at least three years from the end of the year in which the documents are drawn up, stock records drawn up by 12-month period giving details, per month and per product, of any sale or transfer of milk or milk products.Producers whose individual reference quantity of direct sales is 5000 kg or more shall also keep records of milk and milk products which have been produced but not sold or transferred.Member States may lay down more detailed rules.They shall also keep available for the competent authority the registers of livestock held on holdings and used for milk production, in accordance with Article 7 of Regulation (EC) No 1760/2000, and supporting documents enabling such stock records to be verified.