Perhaps you should try some spelling variations:
duale studium » duales studium, dualen studium
da literatura » la literatura, a literatura, de literatura
dd filosofia » de filosofia, da filosofia, la filosofia
di filosofia » la filosofia, e filosofia

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: "test ((duale studium) OR (das studium)) ((dd filosofia) OR (di filosofia)) da literatura".
• Adding a wildcard symbol may retrieve word variants: test ((duale studium) OR (das studium)) ((dd filosofia) OR (di filosofia)) da literatura*.