Perhaps you should try some spelling variations:
duales studium » das studium
ds filosofica » di filosofia, de filosofia, da filosofia
la literatura » la litterature, a literature
e filosofia » la filosofia
des duales » des dualen, des iguales, das duale

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: des duales studium ((ds filosofica) OR (e filosofia)) la literatura.
• Adding a wildcard symbol may retrieve word variants: des duales studium ((ds filosofica) or (e filosofia)) la literatura*.