Perhaps you should try some spelling variations:
da literatura » la literatura, a literatura, de literatura
tests stable » tests table, sets stable, test table
de filosofia » e filosofia, di filosofia, la filosofia
filosofia da » filosofia de, filosofia del, filosofia e
tests scale » sets scale, tests safe, tests shall
test scale » best scale, rest scale, treat scale
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 scale) OR (((tests scale) OR (tests stable)))) studies de filosofia da literatura*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((test scale) or (((tests scale) OR (tests stable)))) studies de filosofia da literatura*".