paragraph_text: Many countries have specific conventions for classifying call signs by transmitter characteristics and location. The call sign format for radio and television call signs follows a number of conventions. All call signs begin with a prefix assigned by the International Telecommunications Union. For example, the United States has been assigned the following prefixes: ``AAA ''--`` ALZ'', ``K '',`` N'', ``W ''. For a complete list, see international call sign allocations.

paragraph_text: The Soviet invasion of Poland was a Soviet military operation that started without a formal declaration of war on 17 September 1939. On that morning, 16 days after Germany invaded Poland from the west, the Soviet Union invaded Poland from the east. Subsequent military operations lasted for the following 20 days and ended on 6 October 1939 with the two - way division and annexation of the entire territory of the Second Polish Republic by both Germany and the Soviet Union. The joint German - Soviet invasion of Poland was secretly agreed to following the signing of the Molotov - Ribbentrop Pact on 23 August 1939.

paragraph_text: As African states became independent in the 1960s, the Soviet Union offered many of their citizens the chance to study in Russia. Over a period of 40 years, about 400,000 African students from various countries moved to Russia to pursue higher studies, including many Black Africans. This extended beyond the Soviet Union to many countries of the Eastern bloc.

paragraph_text: Stages of a Long Journey is a live album by German double bassist and composer Eberhard Weber recorded in Germany in 2005 and released on the ECM label.

paragraph_text: Sassou Nguesso aligned the country with the Eastern Bloc and signed a twenty-year friendship pact with the Soviet Union. Over the years, Sassou had to rely more on political repression and less on patronage to maintain his dictatorship.

paragraph_text: Systematic POW labor in the Soviet Union is associated primarily with the outcomes of World War II and covers the period of 1939-1956, from the official formation of the first POW camps, to the repatriation of the last POWs, from the Kwantung Army.

paragraph_text: The most extreme case was the Soviet Union, and this model may still be followed in some countries: it was a separate service, on a par with the navy or ground force. In the Soviet Union this was called Voyska PVO, and had both fighter aircraft and ground-based systems. This was divided into two arms, PVO Strany, the Strategic Air defence Service responsible for Air Defence of the Homeland, created in 1941 and becoming an independent service in 1954, and PVO SV, Air Defence of the Ground Forces. Subsequently these became part of the air force and ground forces respectively

paragraph_text: On August 19, the 1939 German–Soviet Commercial Agreement was finally signed. On 21 August, the Soviets suspended Tripartite military talks, citing other reasons. That same day, Stalin received assurance that Germany would approve secret protocols to the proposed non-aggression pact that would place half of Poland (border along the Vistula river), Latvia, Estonia, Finland, and Bessarabia in the Soviets' sphere of influence. That night, Stalin replied that the Soviets were willing to sign the pact and that he would receive Ribbentrop on 23 August.

paragraph_text: Following the August 1991 Soviet coup d'état attempt, the State Council of the Union of Soviet Socialist Republics (USSR) (), but also known as the State Soviet, was formed on 5 September 1991 and was designed to be one of the most important government offices in Mikhail Gorbachev's Soviet Union. The members of the council consisted of the President of the Soviet Union, and highest officials (which typically was presidents of their republics) from the Soviet Union Republics. During the period of transition it was the highest organ of state power, having the power to elect a premier, or a person who would take Gorbachev's place if absent; the office of Vice President of the Soviet Union had been abolished following the failed August Coup that very same year.

paragraph_text: Cooperation ended in 1933, as Adolf Hitler came to power and created Nazi Germany. The countries' economic relationship dwindled at the beginning of the Nazi era, but some diplomatic initiatives continued through the 1930s, culminating with the Molotov -- Ribbentrop Pact of 1939 and various trade agreements. Few questions concerning the origins of the Second World War are more controversial and ideologically loaded than the issue of the policies of the Soviet Union under Joseph Stalin towards Nazi Germany between the Nazi seizure of power and the German invasion of the USSR on June 22, 1941.

paragraph_text: The Molotov -- Ribbentrop Pact, also known as the Nazi -- Soviet Pact, the German -- Soviet Non-aggression Pact or the Nazi German - Soviet Pact of Aggression (officially: Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics), was a neutrality pact between Nazi Germany and the Soviet Union signed in Moscow on 23 August 1939 by foreign ministers Joachim von Ribbentrop and Vyacheslav Molotov, respectively. The pact was followed by the German - Soviet Commercial Agreement in February 1940.

paragraph_text: The stated clauses of the Nazi-Soviet non-aggression pact were a guarantee of non-belligerence by each party towards the other, and a written commitment that neither party would ally itself to, or aid, an enemy of the other party. In addition to stipulations of non-aggression, the treaty included a secret protocol that divided territories of Romania, Poland, Lithuania, Latvia, Estonia, and Finland into German and Soviet "spheres of influence", anticipating potential "territorial and political rearrangements" of these countries. Thereafter, Germany invaded Poland on 1 September 1939. After the Soviet–Japanese ceasefire agreement took effect on 16 September, Stalin ordered his own invasion of Poland on 17 September. Part of southeastern (Karelia) and Salla region in Finland were annexed by the Soviet Union after the Winter War. This was followed by Soviet annexations of Estonia, Latvia, Lithuania, and parts of Romania (Bessarabia, Northern Bukovina, and the Hertza region). Concern about ethnic Ukrainians and Belarusians had been proffered as justification for the Soviet invasion of Poland. Stalin's invasion of Bukovina in 1940 violated the pact, as it went beyond the Soviet sphere of influence agreed with the Axis.

paragraph_text: Joseph Stalin was also upset by the results of the Munich conference. The Soviets, who had a mutual military assistance treaty with Czechoslovakia, felt betrayed by France, who also had a mutual military assistance treaty with Czechoslovakia. The British and French, however, mostly used the Soviets as a threat to dangle over the Germans. Stalin concluded that the West had actively colluded with Hitler to hand over a Central European country to the Nazis, causing concern that they might do the same to the Soviet Union in the future, allowing the partition of the USSR between the western powers and the fascist Axis. This belief led the Soviet Union to reorient its foreign policy towards a rapprochement with Germany, which eventually led to the signing of the Molotov - Ribbentrop Pact in 1939.

paragraph_text: When World War II started in 1939, it divided the world into two alliances—the Allies (the United Kingdom and France at first in Europe, China in Asia since 1937, followed in 1941 by the Soviet Union, the United States); and the Axis powers consisting of Germany, Italy and Japan.[nb 1] During World War II, the United States, United Kingdom, and Soviet Union controlled Allied policy and emerged as the "Big Three". The Republic of China and the Big Three were referred as a "trusteeship of the powerful"  and were recognized as the Allied "Big Four" in Declaration by United Nations in 1942. These four countries were referred as the "Four Policemen" of the Allies and considered as the primary victors of World War II. The importance of France was acknowledged by their inclusion, along with the other four, in the group of countries allotted permanent seats in the United Nations Security Council.

paragraph_text: The Following Morning is an album by German double bassist and composer Eberhard Weber recorded in 1976 and released on the ECM label.

paragraph_text: Soviet propaganda and representatives went to great lengths to minimize the importance of the fact that they had opposed and fought against the Nazis in various ways for a decade prior to signing the Pact. Upon signing the pact, Molotov tried to reassure the Germans of his good intentions by commenting to journalists that "fascism is a matter of taste". For its part, Nazi Germany also did a public volte-face regarding its virulent opposition to the Soviet Union, though Hitler still viewed an attack on the Soviet Union as "inevitable".[citation needed]

paragraph_text: In a nationally televised speech early in the morning of December 25, 1991, Gorbachev resigned as president of the USSR – or, as he put it, "I hereby discontinue my activities at the post of President of the Union of Soviet Socialist Republics." He declared the office extinct, and all of its powers (such as control of the nuclear arsenal) were ceded to Yeltsin. A week earlier, Gorbachev had met with Yeltsin and accepted the fait accompli of the Soviet Union's dissolution. On the same day, the Supreme Soviet of the Russian SFSR adopted a statute to change Russia's legal name from "Russian Soviet Federative Socialist Republic" to "Russian Federation," showing that it was now a sovereign state.

paragraph_text: The PTBT was signed by the governments of the Soviet Union, United Kingdom, and United States in Moscow on 5 August 1963 before being opened for signature by other countries. The treaty formally went into effect on 10 October 1963. Since then, 123 other states have become party to the treaty. Ten states have signed but not ratified the treaty.

paragraph_text: Throughout the 1970s, both the Soviet Union and United States replaced old missiles and warheads with newer, more powerful and effective ones. This continued to worsen Soviet - U.S relations. On June 18, 1979, the SALT II treaty was signed in Vienna. This treaty limited both sides' nuclear arsenals and technology. However, this treaty as well as the era of the détente ended with the Soviet Union's invasion of Afghanistan in January, 1980. The United States once again significantly increased military and nuclear spending, while the Soviets were unable to respond and continued to pursue the détente.

paragraph_text: In the early 1930s, the worldwide Great Depression hit Germany hard, as unemployment soared and people lost confidence in the government. In January 1933, Adolf Hitler was appointed Chancellor of Germany. His Nazi Party quickly established a totalitarian regime, and Nazi Germany made increasingly aggressive territorial demands, threatening war if they were not met. Remilitarization of the Rhineland came in 1936, then annexation of Austria in the Anschluss and parts of Czechoslovakia with the Munich Agreement in 1938, and further territory of Czechoslovakia in 1939. On 1 September 1939, Germany initiated World War II in Europe with the invasion of Poland. After forming a pact with the Soviet Union in 1939, Hitler and Stalin divided Eastern Europe. After a "Phoney War" in spring 1940, the Germans swept Denmark and Norway, the Low Countries, and France, giving Germany control of nearly all of Western Europe. Hitler invaded the Soviet Union in June 1941.

Question: What did the soviet union and the performer of The Following Morning's country sign in 1939?
Answer: Molotov -- Ribbentrop Pact of 1939