Perhaps you should try some spelling variations:
y literatura » la literatura
sets scales » sets scale, sets scaled, sets locales
studies doe » studies does, studies dose, studies do
filosofia y » filosofia e, filosofia _, filosofia de
studies de » studies der, studies die, studies due

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: "sets scales ((studies de) OR (studies doe)) filosofia y literatura".
• Adding a wildcard symbol may retrieve word variants: sets scales ((studies de) OR (studies doe)) filosofia y literatura*.