Perhaps you should try some spelling variations:
le literature » e literature, 2e literature, ce literature
filosofia le » filosofia de, filosofia e, filosofia del
tests scale » tests stable, tests safe, tests shall
sets scale » sets scaled, sets scales, set scale
studien e » studien es, studien 3, studien 4

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: ((tests scale) OR (sets scale)) ((studien e) OR (studien _)) filosofia le literature*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tests scale) or (sets scale)) ((studien e) OR (studien _)) filosofia le literature*".