Perhaps you should try some spelling variations:
stable studied » state studied, table studies, unstable studies
le literature » e literature, 2e literature, ce literature
tests stable » tests table, sets stable, test table
i filosofia » di filosofia, a filosofia, y filosofia
e filosofia » la 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 studied ((i filosofia) OR (e filosofia)) le literature".
• Adding a wildcard symbol may retrieve word variants: tests stable studied ((i filosofia) OR (e filosofia)) le literature*.