Commission Regulation (EEC) No 2821/88 of 13 September 1988 amending Regulation (EEC) No 1070/87 laying down detailed rules for the application of Regulation (EEC) No 775/87 temporarily withdrawing a proportion of the reference quantities mentioned in Article 5c (1) of Regulation (EEC) No 804/68 on the common organization of the market in milk and milk products