Perhaps you should try some spelling variations:
stable student » table student, scale student, enable students
der filosofia » de filosofia, e filosofia, da filosofia
tests stable » tests table, sets stable, test table
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: "tests stable student ((der filosofia) OR (di filosofia)) _ literatura".
• Adding a wildcard symbol may retrieve word variants: tests stable student ((der filosofia) OR (di filosofia)) _ literatura*.