Perhaps you should try some spelling variations:
"factores climaticos" » "factores explicativos"
"factores politicos" » "valores politicos", "factores biologicos", "efectos politicos"
"actos politicos" » "aspectos politicos", "efectos politicos", "ciclos politicos"
"factores criticos" » "factores critico", "factores critica", "factores critical"

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: (((("factores politicos") OR ("factores climaticos"))) OR ((((("actores politicos") OR ("actos politicos"))) OR ("factores criticos"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"factores politicos\") OR (\"factores climaticos\"))) or (((((\"actores politicos\") or (\"actos politicos\"))) or (\"factores criticos\"))))~".
• Removing quotes may allow a broader search: (((( factores politicos ) OR ( factores climaticos ))) or ((((( actores politicos ) or ( actos politicos ))) or ( factores criticos ))))~.
• Adding a wildcard symbol may retrieve word variants: (((("factores politicos") OR ("factores climaticos"))) or ((((("actores politicos") or ("actos politicos"))) or ("factores criticos"))))*.