Perhaps you should try some spelling variations:
doubles studium » duales studium
del literatura » de literatura, pela literatura, da literatura
dd filosofia » di filosofia, de filosofia, la filosofia
da filosofia » la filosofia, di filosofia, a filosofia

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: (test OR text) doubles studium ((dd filosofia) OR (da filosofia)) del literatura.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(test or text) doubles studium ((dd filosofia) OR (da filosofia)) del literatura".
• Adding a wildcard symbol may retrieve word variants: (test or text) doubles studium ((dd filosofia) OR (da filosofia)) del literatura*.