Perhaps you should try some spelling variations:
e letterature » et litterature, de litterature, e literature
e letteratura » y literatura, e literatur
beste der » besten der, beste oder, besteht der
studie y » studie 2, studie 1, studie 3

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: beste der ((studie y) OR (studie _)) filosofia ((e letterature) OR (e letteratura)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "beste der ((studie y) or (studie _)) filosofia ((e letterature) OR (e letteratura))".
• Adding a wildcard symbol may retrieve word variants: beste der ((studie y) or (studie _)) filosofia ((e letterature) OR (e letteratura))*.