Wikipedia
Berlinka is the informal Polish and Russian name given to sections of the unfinished Reichsautobahn Berlin-Königsberg, which was a pre-World War II German Reichsautobahn project to connect Berlin with Königsberg in East Prussia. In the late 1930s, the sections near these two cities were finished, but not the larger section in between. The German demand in 1939 to run this road across the Polish Corridor with extraterritorial status and Poland's refusal to allow this was an important element in the tensions that led to the start of World War II. After the war, the German Democratic Republic, the People's Republic of Poland and the Soviet Union's Kaliningrad Oblast inherited the remnants.
The Berlinka is the Polish name for a German collection of historic material which was originally kept at the Preußische Staatsbibliothek zu Berlin, the Prussian State Library at Berlin, but which is now kept in the Jagiellonian Library in Kraków.