Perhaps you should try some spelling variations:
pela literatura » pena literatura, la literatura, a literatura
filosofia pela » filosofia della, filosofia del, filosofia para
der filosofia » de filosofia, e filosofia, di filosofia
drugs studied » drugs studies, drug studies, brass studied
drug studie » drug studies, drugs studies, drug study

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: "tests ((drug studie) OR (drugs studied)) der filosofia pela literatura".
• Adding a wildcard symbol may retrieve word variants: tests ((drug studie) OR (drugs studied)) der filosofia pela literatura*.