Perhaps you should try some spelling variations:
peers studien » peer studie, peer studies, plebs studien
de literatura » de litterature, la literatura, a literatura
y literatura » la literatura
y filosofia » e filosofia, a filosofia, la filosofia
best peers » best peer, best peere, best papers
studien y » studien _, studien 3, studien 4

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 y filosofia ((de literatura) OR (y literatura)).
• Adding a wildcard symbol may retrieve word variants: best peers studien y filosofia ((de literatura) or (y literatura))*.