Pensioners, who usually get their payments at the end of the month, wait outside a closed bank in Thessaloniki, Greece, on Monday. Greece's government announced capital controls, and the country's banks remained closed Monday. Giannis Papanikos/AP hide caption

itoggle caption Giannis Papanikos/AP

Berlin's Humboldt University — named for its founder, the 19th century philosopher and linguist Wilhelm von Humboldt, and his brother, naturalist Alexander von Humboldt, pictured here — is one of several German universities attracting U.S. students. More than 4,000 Americans are studying in German universities. Markus Schreiber/AP hide caption

itoggle caption Markus Schreiber/AP

People stand in a line to use the ATMs of a bank in the northern Greek city of Thessaloniki on Saturday after the country's prime minister announced a snap referendum on an international bailout — pushing Athens toward a Tuesday deadline for a plan to prevent default on its IMF debt. Giannis Papanikos/AP hide caption

itoggle caption Giannis Papanikos/AP