Perhaps you should try some spelling variations:
del literatura » de literatura, pela literatura, da literatura
tests during » protests during, testing during, forests during
costs during » costs using
di filosofia » la filosofia, e filosofia
studie di » studie die, studie d, studie de

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: ((tests during) OR (costs during)) studie di filosofia del literatura.
• Adding a wildcard symbol may retrieve word variants: ((tests during) or (costs during)) studie di filosofia del literatura*.