Perhaps you should try some spelling variations:
advanced courses » advanced course, advanced countries, advanced cases
from barcelona » fc barcelona, von barcelona, two barcelona
book barcelona » books barcelona, von barcelona, two barcelona
pers barcelona » der barcelona, de barcelona, near barcelona

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

• If you are trying to use Boolean operators, they must be ALL CAPS: advanced courses in mathematics - ((((from barcelona) OR (book barcelona))) OR (pers barcelona)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "advanced courses in mathematics - ((((from barcelona) OR (book barcelona))) or (pers barcelona))".
• Adding a wildcard symbol may retrieve word variants: advanced courses in mathematics - ((((from barcelona) OR (book barcelona))) or (pers barcelona))*.