Perhaps you should try some spelling variations:
advanced countries » advanced control, advanced course, advanced queries
advanced courses » advanced course, advanced cases, advanced classes
city barcelona » die barcelona, life barcelona, view barcelona

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((advanced courses) OR (advanced countries)) in mathematics - city barcelona".
• Adding a wildcard symbol may retrieve word variants: ((advanced courses) OR (advanced countries)) in mathematics - city barcelona*.