Perhaps you should try some spelling variations:
advanced controls » advanced controllers, advanced countries, advanced concepts
pers barcelona » der barcelona, de barcelona, near barcelona
crm barcelona » from barcelona, city barcelona, wism 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 controls) OR (advanced control)) in mathematics - ((crm barcelona) OR (pers barcelona)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((advanced controls) or (advanced control)) in mathematics - ((crm barcelona) OR (pers barcelona))".
• Adding a wildcard symbol may retrieve word variants: ((advanced controls) or (advanced control)) in mathematics - ((crm barcelona) OR (pers barcelona))*.