Perhaps you should try some spelling variations:
orale studien » duale studien, frage studien, scale studien
frage stellen » fragen stellen
ds filosofia » di filosofia, de filosofia, da filosofia
e literature » e literatur, life literature, prose literature
filosofia e » filosofia de, filosofia del

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 ((orale studien) OR (frage stellen)) ds filosofia e literature.
• Adding a wildcard symbol may retrieve word variants: test ((orale studien) or (frage stellen)) ds filosofia e literature*.