Perhaps you should try some spelling variations:
safety studien » safety studies, safety study, safety stories
stents safety » agents safety, events safety, tenth safety
die filosofia » di filosofia, e filosofia, da filosofia
de filosofia » e filosofia, di filosofia, la filosofia
a literatura » la literatura, a literature, y literatura

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