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

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