Perhaps you should try some spelling variations:
"de factores" » "de actores", "que factores", "de sectores", "de factres", "de factsres"
"dose factor" » "noise factor", "one factor", "mode factor", "dose factr", "dose factsr"
"de facto" » "de fact", "de facts"

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: (("de facto") OR ((("de factores") OR ("dose factor")))).
• Removing quotes may allow a broader search: (( de facto ) or ((( de factores ) or ( dose factor )))).
• Adding a wildcard symbol may retrieve word variants: (("de facto") or ((("de factores") or ("dose factor"))))*.