Perhaps you should try some spelling variations:
"_ duncan smith" » "_ duncan sarah", "_ duncan scott"
"jon duncan shaw" » "jon duncan sarah", "john duncan shaw", "j duncan shaw", "colin duncan shaw"
"ian duncan sir" » "brian duncan sir", "a duncan sir", "innes duncan sir", "ian duncan i", "ian 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 ((("ian duncan sir") OR ("jon duncan shaw")))).
• Removing quotes may allow a broader search: (( _ duncan smith ) or ((( ian duncan sir ) or ( jon duncan shaw )))).
• Adding a wildcard symbol may retrieve word variants: (("_ duncan smith") or ((("ian duncan sir") or ("jon duncan shaw"))))*.