Perhaps you should try some spelling variations:
filosofica de » filosoficas de, filosofia de, filosofica da
de literatura » de litterature, la literatura, y literatura
test dualen » des dualen, test doubles
studium des » studium der
studium ds » studium das, studium d, studium der

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 dualen ((studium ds) OR (studium des)) filosofica de literatura*".