Perhaps you should try some spelling variations:
del literatur » model literatur, teil literatur, igel literatur
texts social » tests social, texas social, text social
studien der » studie der, studenten der
studien di » studien die, studien dd, studien bei

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: "texts social ((studien di) OR (studien der)) filosofia del literatur*".