Regulation (EEC) No 1331/75 of the Commission of 26 May 1975 amending Regulations (EEC) No 2637/70, (EEC) No 586/75, (EEC) No 783/75 and (EEC) No 784/75 laying down detailed rules for the application of the system of export licences in the field of tenders for the levy and/or the refund on exports of rice to third countries