Perhaps you should try some spelling variations:
des studien » das studien, des studie, die studien
y filosofia » e filosofia, a filosofia, la filosofia
filosofia e » filosofia de, filosofia del
studien y » studien _, studien 3, studien 4
test des » test der, test test

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: test des studien y filosofia e (literatur* OR literature*).
• Adding a wildcard symbol may retrieve word variants: test des studien y filosofia e (literatur* or literature*)*.