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

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