Perhaps you should try some spelling variations:
de literatura » de litterature, la literatura, y literatura
di filosofia » la filosofia, e filosofia
de filosofia » e filosofia, la filosofia, a filosofia
due studien » die studien, aue studien, duale studien
tests due » tests die, tests de, tests drug

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "tests due studien ((de filosofia) OR (di filosofia)) de literatura*".