Commission Regulation (EEC) No 657/92 of 16 March 1992 amending Regulation (EEC) No 3743/91 laying down detailed rules for the application of the import arrangements provided for by Council Regulations (EEC) No 3668/91 and (EEC) No 3669/91 in the beef and veal sectors, and Regulation (EEC) No 3744/91 laying down detailed rules for the application of import arrangements provided for in Council Regulation (EEC) No 3670/91 for frozen thin skirt of bovine animals