Perhaps you should try some spelling variations:
la literature » la litterature, a literature, la literatura
studien eine » studie eine, studien die, studium eine
filosofia la » filosofia da, filosofia le, filosofica da
tests scale » tests stable, sets scale, tests safe
studien e » studien es, studien _, studien 3

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 ((studien e) OR (studien eine)) filosofia la literature.
• Adding a wildcard symbol may retrieve word variants: tests scale ((studien e) or (studien eine)) filosofia la literature*.