Perhaps you should try some spelling variations:
de litterature » la litterature, et litterature
de literatura » la literatura, y literatura, a literatura
social studie » social studio, sociale studies, sociali studies
de filosofia » e filosofia, di filosofia, la filosofia

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: ist ((social studie) OR (social studies)) de filosofia ((de literatura) OR (de litterature)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "ist ((social studie) or (social studies)) de filosofia ((de literatura) OR (de litterature))".
• Adding a wildcard symbol may retrieve word variants: ist ((social studie) or (social studies)) de filosofia ((de literatura) OR (de litterature))*.