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

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