Perhaps you should try some spelling variations:
stents safety » agents safety, tenth safety, tests safety
events safety » agents safety, plants safety
die filosofia » di filosofia, de filosofia, e filosofia
de literatura » de litterature, la literatura, y literatura
filosofia de » filosofia del
studien die » studie die, studien der

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 (events safety)) studien die filosofia de literatura".
• Adding a wildcard symbol may retrieve word variants: ((stents safety) OR (events safety)) studien die filosofia de literatura*.