Perhaps you should try some spelling variations:
stents safety » agents safety, events safety, tests safety
da literatura » la literatura, a literatura, de literatura
tenth safety » heath safety, kent safety, ninth safety
filosofia da » filosofia de, filosofia del, filosofia e
study la » study law, study lay, study lca

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: "((stents safety) OR (tenth safety)) study la filosofia da literatura*".