++++ 1.Common commercial policy - Protection against dumping practices - Conduct of the procedure - Duration exceeding one year - Whether permissible - Condition - Reasonable period ( Council Regulation No 3017/79, Art . 7(9 ) ) 2.Common commercial policy - Protection against dumping practices - Dumping margin - Determination of the normal value - Factor to be given priority - Price charged in the ordinary course of trade - Impossibility of taking it into account owing to the low sales of the representative exporting undertakings on the domestic market - Constructed value ( Council Regulation No 3017/79, Art . 2B(3)(a ) and ( b ) ) 3.Common commercial policy - Protection against dumping practices - Imposition of definitive anti-dumping duties - Retroactive effect - Prohibited - Derogation - Retroactive effect covering the period of application of the provisional anti-dumping duties - Absence of transitional provisions applicable to imports effected in pursuance of earlier contracts - Principle of the protection of legitimate expectation - Breach - None Council Regulation No 3017/79, Arts 11, 12 and 13(4)(a ) )