Perhaps you should try some spelling variations:
di filosofia » la filosofia, e filosofia
a literatura » la literatura, a literature, y literatura
filosofia a » filosofia da, filosofia la, filosofia e
des dualen » des idealen
studium di » studium die, studium i, studium ii

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((des dualen) OR (der dualen)) studium di filosofia a literatura".
• Adding a wildcard symbol may retrieve word variants: ((des dualen) OR (der dualen)) studium di filosofia a literatura*.