Perhaps you should try some spelling variations:
model literatur » modell literatur, model literature, moden literatur
del literatur » teil literatur, igel literatur, l literatur
texto social » text social, texts social, texas social
studien die » studie die, studien der
studien de » studien der, studien des, studien dd

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: texto social ((studien de) OR (studien die)) filosofia ((del literatur) OR (model literatur)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "texto social ((studien de) or (studien die)) filosofia ((del literatur) OR (model literatur))".
• Adding a wildcard symbol may retrieve word variants: texto social ((studien de) or (studien die)) filosofia ((del literatur) OR (model literatur))*.