Perhaps you should try some spelling variations:
de literatuur » de literatura, en literatuur, de litterature
des studien » das studien, des studie, die studien
3 filosofia » e filosofia, y filosofia, _ filosofia
a filosofia » la filosofia, e filosofia, di filosofia
test des » test der, test test

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: "test des studien ((3 filosofia) OR (a filosofia)) de literatuur*".