Perhaps you should try some spelling variations:
de litterature » la litterature, et litterature
filosofia de » filosofia del
studien des » studien der, studie des, studien aus
test scale » tests scale, best scale, rest scale
studien ds » studien das, studies ds, studien dd

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 scale ((studien ds) OR (studien des)) filosofia de litterature.
• Adding a wildcard symbol may retrieve word variants: test scale ((studien ds) or (studien des)) filosofia de litterature*.