Perhaps you should try some spelling variations:
suitable studies » table studies, unstable studies, suitability studies
test suitable » best suitable, most suitable, notes suitable
filosofica a » filosofica da, filosofica _, filosofico a
filosofica e » filosofia e, filosofica da, filosofia de
studies de » studies der, studies die, studies doe

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: test suitable studies de ((filosofica a) OR (filosofica e)) literatura*.