Perhaps you should try some spelling variations:
modell studien » model studies, models studies, moderne studien
de literatura » de litterature, la literatura, a literatura
y literatura » la literatura
rosi modell » osi modell, osi model, osi modells
5 filosofia » e filosofia, a filosofia, y filosofia
studien 5 » 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: rosi modell studien 5 filosofia ((de literatura) OR (y literatura)).
• Adding a wildcard symbol may retrieve word variants: rosi modell studien 5 filosofia ((de literatura) or (y literatura))*.