Perhaps you should try some spelling variations:
"dde factor" » "dose factor", "mode factor", "one factor", "dde facto", "de factor", "ddose factor", "ddde factor", "dde factorr", "ddex factor", "dde factoor", "dde faitor"
"de factor" » "de facto", "e factor", "dose factor", "dde factor", "de factorr", "dex factor", "de factoor", "de faitor"
"e facto" » "de facto", "e factor", "ex facto"
"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: (((("e facto") OR ("de fact"))) OR ((("de factor") OR ("dde factor")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"e facto\") or (\"de fact\"))) or (((\"de factor\") OR (\"dde factor\"))))".
• Removing quotes may allow a broader search: (((( e facto ) or ( de fact ))) or ((( de factor ) OR ( dde factor )))).
• Adding a wildcard symbol may retrieve word variants: (((("e facto") or ("de fact"))) or ((("de factor") OR ("dde factor"))))*.