 Complete the following phrase:  On June 6, 1950, a declaration was signed between the government of the Polish Peoples Republic and the German Democratic Republic on the demarcation of the existing Polish-German border on the OderNeisse line. After the initial agreement, both countries concluded the Treaty of Zgorzelec. The border was recognized by West Germany in 1970 in the Treaty of Warsaw, and by reunified Germany, in 1990 in the 