 Complete the following phrase:  Due to developed economic relations and the large expat community, relations with West Germany played a particularly important role in the set of Yugoslav bilateral relations with the EEC member states. Formal bilateral relations between Yugoslavia and West Germany were canceled in accordance to the Hallstein Doctrine after the 1957 Yugoslav recognition of East Germany limiting relations almost exclusively to the economics field. In 1965 expert negotiations with EEC began as well as talks on extent of future economic cooperation and potential trade exchange. Relations were reestablished after the election of Willy Brandt and his 1968 visit to Yugoslavia within his Ostpolitik efforts. Tito and Brandt discussed war reparations leading to the creation of the so-called Brioni Formula focused on development aid and loans under highly generous conditions instead of formal reparations. This formula enabled Yugoslavia to receive up to 1 billion Deutsche Mark and was subsequently used with Poland. Belgrade expressed its dissatisfaction with the unequal treatment of numerous Yugoslav workers in Germany compared to Italian, Spanish and Turkish workers, and with the activities of nationalist emigration groups. There was also dissatisfaction with some of the ceremonial aspect of Ostpolitik in which the Socialist Republic of Romania normalized its relations with West Germany before Yugoslavia and in which famous 1970 Kniefall von Warschau in Warsaw was not followed by similar gesture to victims of the 