Germany; political history and theory; 20th century; western zones, Federal Republic of Germany - BRD, reunited Germany after 3 October 1990; German cleavage, relations with DDR, unification / Duitsland; politieke geschiedenis en theorie; 19e en 20e eeuw; de Westelijke zones, Bundesrepublik Deutschland, herenigd Duitsland na 3 oktober 1990; hereniging Duitsland / Germany; political history and theory; 20th century; eastern zone, German Democratic Republic, special problems of former DDR areas; Wende - revolution 1989 - 3 October 1990 / Duitsland; politieke geschiedenis en theorie; 19e en 20e eeuw; de oostelijke zone, Deutsche Demokratische Republik en voormalige DDR- gebieden; omwenteling 1989 en 1990 tot 3 oktober 1990 / Germany; political history and theory; 20th century; eastern zone, German Democratic Republic, special problems of former DDR areas; German cleavage, relations with BRD, unification