Perhaps you should try some spelling variations:
filosofica da » filosofia da, filosofia de, filosofia di
da literatura » la literatura, a literatura, de literatura
tests scale » tests stable, sets scale, tests safe
studien e » studien es, studien _, studien 4
studien 3 » studien _, studien 4, studien 5

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 3)) filosofica da literatura".
• Adding a wildcard symbol may retrieve word variants: tests scale ((studien e) OR (studien 3)) filosofica da literatura*.