Perhaps you should try some spelling variations:
le literature » e literature, 2e literature, ce literature
filosofia le » filosofia de, filosofia e, filosofia del
tests duale » tests due, tests scale, tests damage
studien es » studien aus, studien bei, studien ein
studien e » studien _, studien 3, studien 4

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 duale ((studien e) OR (studien es)) filosofia le literature*".