Perhaps you should try some spelling variations:
delle studien » delphi studien, modell studien, welche studien
duale studien » duale studium, scale studien, duales studium
de literatura » de litterature, la literatura, y literatura
de filosofia » e filosofia, di filosofia, la filosofia
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 ((delle studien) OR (duale studien)) de filosofia de literatura.
• Adding a wildcard symbol may retrieve word variants: test ((delle studien) or (duale studien)) de filosofia de literatura*.