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
la literatura » la litterature, a literature
de filosofia » e filosofia, di filosofia, la filosofia

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