Question: Robert Johann Maria König was born in a city approximately 30 km south of what?

Related documents: [0]  [DOC] Linz ( ; ] ; Czech: "Linec" ) is the third-largest city of Austria and capital of the state of Upper Austria (German: "Oberösterreich" ). It is in the north centre of Austria, approximately 30 km south of the Czech border, on both sides of the River Danube. The population of the city is , and that of the Greater Linz conurbation is about 271,000. [END] 
[1]  [DOC] Robert Johann Maria König (11 April 1885, Linz – 9 July 1979, Munich) was an Austrian mathematician. [END]  
Answer: Czech border
Czech border