Perhaps you should try some spelling variations:
de literatura » de litterature, la literatura, y literatura
filosofia de » filosofia del
a filosofia » la filosofia, e filosofia, di filosofia
tests case » test case, tests based, tests code
test cases » test case

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 case) OR (test cases)) studies a filosofia de literatura*".