Perhaps you should try some spelling variations:
stents safety » agents safety, events safety, tenth safety
tests safety » test safety, guests safety, lists safety
filosofia de » filosofia del
filosofia e » filosofia del
study de » study die, study der, study dem

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