Perhaps you should try some spelling variations:
"_ duncan smith" » "_ duncan sarah", "_ duncan scott"
"john duncan sir" » "john dunton sir", "john dunning sir", "john duncan sarah"
"john duncan i" » "john dunton i", "john dunning i", "john duncan _", "john duncan m", "john duncan c"
"jon duncan sir" » "j duncan sir", "ian duncan sir", "colin duncan sir", "jon duncan sarah"

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: (("_ duncan smith") OR ((("jon duncan sir") OR ((("john duncan sir") OR ("john duncan i")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"_ duncan smith\") or (((\"jon duncan sir\") or (((\"john duncan sir\") OR (\"john duncan i\"))))))".
• Removing quotes may allow a broader search: (( _ duncan smith ) or ((( jon duncan sir ) or ((( john duncan sir ) OR ( john duncan i )))))).
• Adding a wildcard symbol may retrieve word variants: (("_ duncan smith") or ((("jon duncan sir") or ((("john duncan sir") OR ("john duncan i"))))))*.