Perhaps you should try some spelling variations:
della literatura » della letteratura, pela literatura, nella letteratura
filosofia della » filosofia del, filosofia de
der filosofia » de filosofia, e filosofia, di filosofia
testing drug » testing during, testing data
studie der » studium der
test du » test de, test d, test do

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: ((testing drug) OR (test du)) studie der filosofia della literatura.
• Adding a wildcard symbol may retrieve word variants: ((testing drug) or (test du)) studie der filosofia della literatura*.