Perhaps you should try some spelling variations:
das filosofia » da filosofia, la filosofia, a filosofia
de literatura » de litterature, la literatura, a literatura
di filosofia » la filosofia, e filosofia
y literatura » la literatura
text das » text des, text data, text der

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