Perhaps you should try some spelling variations:
del litterature » de litterature, des litteratures, et litterature
da filosofia » la filosofia, di filosofia, a filosofia
sets scales » sets scaled, sets locales, sites scales
sets scale » sets scaled, set scale, sets stable
study da » study das, study dca, study d

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: ((sets scale) OR (sets scales)) study da filosofia del litterature.
• Adding a wildcard symbol may retrieve word variants: ((sets scale) or (sets scales)) study da filosofia del litterature*.