Perhaps you should try some spelling variations:
la literatura » la litterature
scale studien » scale studies, scale student, duale studien
de filosofia » e filosofia, la filosofia, a 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.

• If you are trying to use Boolean operators, they must be ALL CAPS: tests scale studien ((de filosofia) OR (di filosofia)) ((la literatura) OR (a literature)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tests scale studien ((de filosofia) or (di filosofia)) ((la literatura) OR (a literature))".
• Adding a wildcard symbol may retrieve word variants: tests scale studien ((de filosofia) or (di filosofia)) ((la literatura) OR (a literature))*.