Perhaps you should try some spelling variations:
di filosofia » la filosofia, e filosofia
wozu studien » zu studien, zu studie
y literatura » la literatura
a filosofia » la filosofia, e filosofia
test wozu » test work, des wozu, tell wozu

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 wozu studien ((a filosofia) OR (di filosofia)) y literatura".
• Adding a wildcard symbol may retrieve word variants: test wozu studien ((a filosofia) OR (di filosofia)) y literatura*.