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