Perhaps you should try some spelling variations:
"dose factor" » "noise factor", "one factor", "mode factor"
"age factor" » "age factors", "male factor", "one factor"
"de factor" » "de facto", "e factor", "mode factor"
"de fait" » "de faits", "le fait", "se fait"

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 factor") OR ("age factor"))) OR ("dose factor"))) OR ("de fait"))*.
• Removing quotes may allow a broader search: (((((( de factor ) or ( age factor ))) or ( dose factor ))) or ( de fait ))*.