Perhaps you should try some spelling variations:
pela literatura » pena literatura, la literatura, a literatura
scale studien » scale studies, scale student, duale studien
die filosofia » de filosofia, e filosofia, da filosofia
di filosofia » la filosofia, e filosofia
tests scale » tests stable, sets scale, tests safe

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 studien ((die filosofia) OR (di filosofia)) pela literatura".
• Adding a wildcard symbol may retrieve word variants: tests scale studien ((die filosofia) OR (di filosofia)) pela literatura*.