Perhaps you should try some spelling variations:
del literature » model literature, abel literature, fuel literature
scale studien » scale studies, scale student, duale studien
die filosofia » di filosofia, de filosofia, e filosofia
scale studie » scale studies, scale study, sociale studies

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: sets ((scale studie) OR (scale studien)) die filosofia del literature.
• Adding a wildcard symbol may retrieve word variants: sets ((scale studie) or (scale studien)) die filosofia del literature*.