Perhaps you should try some spelling variations:
die filosofica » di filosofia, de filosofia, e filosofica
studenten die » studenten der, studenten des, studenten und
tests stable » tests table, sets stable, test table
filosofica y » filosofia y, filosofica e, filosofica _
y literatura » la literatura
tests scale » sets scale, tests safe, tests shall

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 scale) OR (tests stable)) studenten die filosofica y literatura".
• Adding a wildcard symbol may retrieve word variants: ((tests scale) OR (tests stable)) studenten die filosofica y literatura*.