Perhaps you should try some spelling variations:
di literatura » de literatura, da literatura, ii literatura
die filosofia » de filosofia, e filosofia, da filosofia
di filosofia » la filosofia, e filosofia
safe studie » safe studio, life studie, case studie
tests safe » tests safety, tests scale, tests space

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 safe studie ((die filosofia) OR (di filosofia)) di literatura*".