Perhaps you should try some spelling variations:
del literatura » de literatura, pela literatura, da literatura
studenten der » studenten und
der filosofia » de filosofia, e filosofia, di filosofia
series style » styles style, series some, series study
series state » services state, series some, series study

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: ((series style) OR (series state)) studenten der filosofia del literatura.
• Adding a wildcard symbol may retrieve word variants: ((series style) or (series state)) studenten der filosofia del literatura*.