Commission Regulation (EEC) No 4137/87 of 9 December 1987 determining the conditions of entry of goods under subheadings 0408 11 90, 0408 19 90, 0408 91 90, 0408 99 90, 1106 20 10, ex 2501 00 51, 3502 10 10 and 3502 90 10 of the combined nomenclature