Perhaps you should try some spelling variations:
de literatura » de litterature, la literatura, y literatura
filosofia de » filosofia del
tests acute » testis acute, testing acute, versus acute
studien das » studie das, studien des, studien der
studien da » studien dar, studien a, studien dd

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 acute ((studien da) OR (studien das)) filosofia de literatura".
• Adding a wildcard symbol may retrieve word variants: tests acute ((studien da) OR (studien das)) filosofia de literatura*.