Sixth 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
Modified by
Council Directive 91/680/EEC of 16 December 1991 supplementing the common system of value added tax and amending Directive 77/388/EEC with a view to the abolition of fiscal frontiers