Perhaps you should try some spelling variations:
"de factoor" » "de facto", "de facteur", "de factooor", "de faitoor", "e factoor"
"e factors" » "age factors", "like factors", "male factors", "one factors"
"e factor" » "one factor", "age factor"
"de fact" » "de facto", "de fait", "e fact"

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 fact") OR ((((("e factor") OR ("e factors"))) OR ("de factoor")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"de fact\") or (((((\"e factor\") OR (\"e factors\"))) or (\"de factoor\"))))".
• Removing quotes may allow a broader search: (( de fact ) or ((((( e factor ) OR ( e factors ))) or ( de factoor )))).
• Adding a wildcard symbol may retrieve word variants: (("de fact") or ((((("e factor") OR ("e factors"))) or ("de factoor"))))*.