Perhaps you should try some spelling variations:
de litterature » la litterature, et litterature
modell studie » modell studien, models studies, models studied
die filosofia » de filosofia, e filosofia, da filosofia
di filosofia » la filosofia, e filosofia
text modell » text model, text models, text mode

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "text modell studie ((die filosofia) OR (di filosofia)) de litterature*".