Perhaps you should try some spelling variations:
de literatura » de litterature, la literatura, y literatura
di filosofia » la filosofia, e filosofia
filosofia de » filosofia del
testo » test, tests, texto

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: testo ((duales studium) OR (das studium)) di filosofia de literatura.
• Adding a wildcard symbol may retrieve word variants: testo ((duales studium) or (das studium)) di filosofia de literatura*.