Perhaps you should try some spelling variations:
des filosofia » e filosofia, di filosofia, da filosofia
tests schule » testes schedule, tests should, tests simple
de filosofia » e filosofia, di filosofia, la filosofia
tests scale » tests stable, sets scale, tests safe

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: ((tests schule) OR (tests scale)) studium ((des filosofia) OR (de filosofia)) a literature.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tests schule) or (tests scale)) studium ((des filosofia) OR (de filosofia)) a literature".
• Adding a wildcard symbol may retrieve word variants: ((tests schule) or (tests scale)) studium ((des filosofia) OR (de filosofia)) a literature*.