Perhaps you should try some spelling variations:
drugs studied » drugs studies, drug studies, groups studied
1 filosofica » e filosofica, y filosofia, _ filosofia
tests drugs » tests drug, test drugs, testing drugs
a filosofia » la filosofia, di filosofia
e filosofia » la filosofia
literatur » literature

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: tests drugs studied ((((1 filosofica) OR (a filosofia))) OR (e filosofia)) e literatur.
• Adding a wildcard symbol may retrieve word variants: tests drugs studied ((((1 filosofica) or (a filosofia))) or (e filosofia)) e literatur*.