Perhaps you should try some spelling variations:
peers studien » peer studie, peer studies, peer student
plebs studien » als studien, des studien, fluss studien
de literatura » de litterature, la literatura, a literatura
y literatura » la literatura
4 filosofia » e filosofia, a filosofia, y filosofia

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: best ((peers studien) OR (plebs studien)) 4 filosofia ((de literatura) OR (y literatura)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "best ((peers studien) OR (plebs studien)) 4 filosofia ((de literatura) or (y literatura))".
• Adding a wildcard symbol may retrieve word variants: best ((peers studien) OR (plebs studien)) 4 filosofia ((de literatura) or (y literatura))*.