Perhaps you should try some spelling variations:
en litterature » et litterature, une litterature, la litterature
test failure » test failures, post failure, fast failure
filosofia en » filosofia e, filosofia del, filosofia con
studien das » studien des, studien der, studien aus
studie das » studie des, studie der, studie am

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 failure ((studie das) OR (studien das)) filosofia en litterature.
• Adding a wildcard symbol may retrieve word variants: test failure ((studie das) or (studien das)) filosofia en litterature*.