http://www.legislation.gov.uk/eudr/1977/388/adoptedSixth Council Directive 77/388/EEC of 17 May 1977 on the harmonization of the laws of the Member States relating to turnover taxes - Common system of value added tax: uniform basis of assessment (repealed)Sixth Council Directive 77/388/EEC (repealed)enQueen's Printer of Acts of Parliament2020-09-26