Perhaps you should try some spelling variations:
filosofica a » filosofica da, filosofica _, filosofico a
filosofica e » filosofia e, filosofica da, filosofia de
zu studie » zu studien, eu studies, zu studium
studie e » studie 2, studie _, studie 1
test zu » test zur, tests zu, test zum

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: "test zu studie e ((filosofica a) OR (filosofica e)) literatura*".