Question: When did East Germany and Ursula Thielemann's country of citizenship unite?

full_context: Document 1: Territorial evolution of Germany: The territorial changes of Germany include all changes in the borders and territory of Germany from its formation in 1871 to the present. Modern Germany was formed in 1871 when Otto von Bismarck unified most of the German states, with the notable exception of Austria, into the German Empire. After the First World War, Germany lost about 10% of its territory to its neighbours and the Weimar Republic was formed. This republic included territories to the east of today's German borders.
Document 2: Uschi Obermaier: Ursula "Uschi" Obermaier (September 24, 1946) is a former fashion model and actress associated with the 1968 left-wing movement in Germany. She is considered an iconic sex symbol of the so-called "1968 generation" and the protests of 1968.
Document 3: Ute Scheiffele: Ute Scheiffele, née Gähler (born 12 February 1941), is a German luger who competed in the 1960s for East and West Germany. She was born in Oybin, Sachsen, East Germany. She never won any medals on World, European or Olympic games with the best result fourth in the 1963 World Championship in Imst, Austria. In 1964 she fled to Bavaria and started for West Germany at the 1968 Winter Olympics in Grenoble.
Document 4: Hockey helmet: In August 1979, then President of the National Hockey League (NHL), John Ziegler, announced that protective helmets would become mandatory for incoming players in the NHL. ``The introduction of the helmet rule will be an additional safety factor, ''he said. The rule allowed players who signed professional contracts prior to June 1, 1979 to continue to not wear a helmet provided a liability waiver was signed, if they so desired. The last player to play without a helmet was Craig MacTavish, who played his final game during the 1996 -- 97 season for the St. Louis Blues.
Document 5: Anneloes Nieuwenhuizen: Anne Lucia Cornelia Maria ("Anneloes") Nieuwenhuizen (born October 16, 1963 in Bussum) is a former Dutch field hockey defender, who won the gold medal with the National Women's Team at the 1984 Summer Olympics.
Document 6: Ursula Thielemann: Ursula ("Ulla") Thielemann (born January 9, 1960) was a field hockey international from West Germany, who won the silver medal with her national squad at the 1984 Summer Olympics in Los Angeles, California. She was the first goalkeeper in women's field hockey to wear a helmet.
Document 7: Germany women's national football team: The German national team is one of the most successful in women's football. They are two-time world champions, having won the 2003 and 2007 tournaments. They are also the only nation to have won both the men's and women's tournament. The team has won eight of the twelve UEFA European Championships, claiming  six consecutive titles between 1995 and 2013. Germany is one of the two nations to win both the men's and women's European tournament, along with the Netherlands. Germany has won Olympic gold in 2016, after three consecutive bronze medals at the Women's Olympic Football Tournament, finishing third in 2000, 2004 and 2008. Birgit Prinz holds the record for most appearances and is the team's all-time leading goalscorer. Prinz has also set international records; she has received the FIFA World Player of the Year award three times and is the joint second overall top goalscorer at the Women's World Cup.
Document 8: Hope Solo: Hope Amelia Solo (born July 30, 1981) is an American soccer goalkeeper, two - time Olympic gold medalist, and World Cup champion. She was the goalkeeper for the United States women's national soccer team from 2000 through August 2016. After playing at the collegiate level for the University of Washington, she played professionally for the Philadelphia Charge in the Women's United Soccer Association (WUSA). When the WUSA folded after her first season, she traveled to Europe to play for the top division leagues in Sweden and France. From 2009 to 2011, she played in the Women's Professional Soccer (WPS) for Saint Louis Athletica, Atlanta Beat and magicJack. After the WPS ceased operations in early 2012, she played for the Seattle Sounders in the W - League. She most recently played for Seattle Reign FC in the National Women's Soccer League, the top division of women's soccer in the United States.
Document 9: Dresden: Since German reunification in 1990 Dresden is again a cultural, educational and political centre of Germany and Europe. The Dresden University of Technology is one of the 10 largest universities in Germany and part of the German Universities Excellence Initiative. The economy of Dresden and its agglomeration is one of the most dynamic in Germany and ranks first in Saxony.  It is dominated by high-tech branches, often called “Silicon Saxony”. The city is also one of the most visited in Germany with 4.3 million overnight stays per year. The royal buildings are among the most impressive buildings in Europe. Main sights are also the nearby National Park of Saxon Switzerland, the Ore Mountains and the countryside around Elbe Valley and Moritzburg Castle. The most prominent building in the city of Dresden is the Frauenkirche. Built in the 18th century, the church was destroyed during World War II. The remaining ruins were left for 50 years as a war memorial, before being rebuilt between 1994 and 2005.
Document 10: Germany: After Germany surrendered, the Allies partitioned Berlin and Germany's remaining territory into four military occupation zones. The western sectors, controlled by France, the United Kingdom, and the United States, were merged on 23 May 1949 to form the Federal Republic of Germany (Bundesrepublik Deutschland); on 7 October 1949, the Soviet Zone became the German Democratic Republic (Deutsche Demokratische Republik). They were informally known as West Germany and East Germany. East Germany selected East Berlin as its capital, while West Germany chose Bonn as a provisional capital, to emphasize its stance that the two - state solution was an artificial and temporary status quo.
Document 11: States of Germany: After the Nazi Party seized power in January 1933, the Länder increasingly lost importance. They became administrative regions of a centralised country. Three changes are of particular note: on January 1, 1934, Mecklenburg-Schwerin was united with the neighbouring Mecklenburg-Strelitz; and, by the Greater Hamburg Act (Groß-Hamburg-Gesetz), from April 1, 1937, the area of the city-state was extended, while Lübeck lost its independence and became part of the Prussian province of Schleswig-Holstein.
Document 12: History of Germany (1945–1990): The intended governing body of Germany was called the Allied Control Council. The commanders - in - chief exercised supreme authority in their respective zones and acted in concert on questions affecting the whole country. Berlin, which lay in the Soviet (eastern) sector, was also divided into four sectors with the Western sectors later becoming West Berlin and the Soviet sector becoming East Berlin, capital of East Germany.
Document 13: Unification of Germany: The unification of Germany into a politically and administratively integrated nation state officially occurred on 18 January 1871, in the Hall of Mirrors at the Palace of Versailles in France. Princes of the German states, excluding Austria, gathered there to proclaim Wilhelm I of Prussia as German Emperor after the French capitulation in the Franco - Prussian War. Unofficially, the de facto transition of most of the German - speaking populations into a federated organization of states had been developing for some time through alliances formal and informal between princely rulers -- but in fits and starts; self - interests of the various parties hampered the process over nearly a century of autocratic experimentation, beginning in the era of the Napoleonic Wars, which saw the dissolution of the Holy Roman Empire of the German Nation (1806), and the subsequent rise of German nationalism.
Document 14: Berlin Wall: In 1989 a series of revolutions in nearby Eastern Bloc countries -- Poland and Hungary in particular -- caused a chain reaction in East Germany that ultimately resulted in the demise of the Wall. After several weeks of civil unrest, the East German government announced on 9 November 1989 that all GDR citizens could visit West Germany and West Berlin. Crowds of East Germans crossed and climbed onto the Wall, joined by West Germans on the other side in a celebratory atmosphere. Over the next few weeks, euphoric people and souvenir hunters chipped away parts of the Wall; the governments later used industrial equipment to remove most of what was left. The ``fall of the Berlin Wall ''paved the way for German reunification, which formally took place on 3 October 1990.
Document 15: German reunification: The German reunification (German: Deutsche Wiedervereinigung) was the process in 1990 in which the German Democratic Republic (GDR / DDR / East Germany) joined the Federal Republic of Germany (FRG / West Germany) to form the reunited nation of Germany, and when Berlin reunited into a single city, as provided by its then Grundgesetz constitution Article 23. The end of the unification process is officially referred to as German unity (German: Deutsche Einheit), celebrated on 3 October (German Unity Day) (German: Tag der deutschen Einheit). Following German reunification, Berlin was once again designated as the capital of united Germany.
ground_truth: 1990
sub_queries: Ursula Thielemann >> country of citizenship Answer: West Germany
when did east germany and West Germany unite Answer: 1990