Perhaps you should try some spelling variations:
le literatura » la literatura, de literatura, e literatura
delle studien » duale studien, delphi studien, modell studien
ds filosofia » de filosofia, da filosofia, la filosofia
di filosofia » la filosofia, e filosofia
test delle » testi delle, tesi delle, test della

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: test delle studien ((ds filosofia) OR (di filosofia)) le literatura.
• Adding a wildcard symbol may retrieve word variants: test delle studien ((ds filosofia) or (di filosofia)) le literatura*.