Perhaps you should try some spelling variations:
"de factor" » "dose factor", "mode factor", "de factores", "de factors", "done factor", "dage factor", "dex factor", "de factr", "d5 factor"
"e factor" » "e factors", "one factor", "age factor", "ex factor", "e factr", "5 factor"
"e facto" » "ex facto", "e fact", "5 facto"
"de facto" » "dex facto", "de fact", "d5 facto"

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