Perhaps you should try some spelling variations:
la literature » la litterature, a literature, la literatura
filosofia la » filosofia da, filosofia le, filosofica da
tests scale » tests stable, sets scale, tests safe
studien ein » studien eine, studieren ein, studien die
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 ein)) filosofia la literature*.