Perhaps you should try some spelling variations:
de factor » dose factor, mode factor, de factores
e factor » e factors, one factor, age factor
e factsr » e factors, e factory, e fact
factor » factr, factsr
facto » fact, facts

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