Perhaps you should try some spelling variations:
"model factor" » "models factor", "model fast", "model factsr"
"de factor" » "e factor", "dose factor", "mode factor", "de faitor", "de falcoor", "de factsr"
"de faitor" » "de fair", "de fait", "de faits"
"de facto" » "de faito", "e facto", "de falcoo", "de facts"
"de fact" » "de fait", "e fact", "de falco"

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 faitor"))) OR ("model factor"))) OR ("de facto"))) OR ("de fact")).
• Removing quotes may allow a broader search: (((((((( de factor ) or ( de faitor ))) or ( model factor ))) or ( de facto ))) or ( de fact )).
• Adding a wildcard symbol may retrieve word variants: (((((((("de factor") or ("de faitor"))) or ("model factor"))) or ("de facto"))) or ("de fact"))*.