91/236/EEC: Commission Decision of 23 April 1991 amending Decision 90/136/EEC approving the draft measures for implementation in the United Kingdom of Article 3b of Regulation (EEC) No 857/84 adopting general rules for the application of the levy referred to in Article 5c of Regulation (EEC) No 804/68 in the milk and milk products sector (Only the English text is authentic)