Perhaps you should try some spelling variations:
safety study » safety stock
de filosofia » e filosofia, di filosofia, la filosofia
e literatura » de literatura, e literatur, a literatura
y literatura » la literatura

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 ((safety study) OR (safety studies)) de filosofia ((e literatura) OR (y literatura)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tests ((safety study) OR (safety studies)) de filosofia ((e literatura) or (y literatura))".
• Adding a wildcard symbol may retrieve word variants: tests ((safety study) OR (safety studies)) de filosofia ((e literatura) or (y literatura))*.