Perhaps you should try some spelling variations:
"de factor" » "de facto", "e factor", "dose factor", "de factoor", "de faitor", "de falcoor", "d_ factor", "d3 factor", "d5 factor"
"de fact" » "de facto", "de fait", "de falco", "d_ fact", "d3 fact", "d5 fact"
"e fact" » "_ fact", "3 fact", "5 fact"
"a fact" » "a face", "a factor"

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