Perhaps you should try some spelling variations:
dualen studium » duales studium, duale studium
di filosofia » la filosofia, e filosofia
e literatura » de literatura, y literatura, e literatur
d filosofia » de filosofia, da filosofia, e filosofia
des dualen » der dualen, des idealen

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: "des dualen studium ((d filosofia) OR (di filosofia)) e literatura*".