Perhaps you should try some spelling variations:
"mr duncan sarah" » "mr duncan adam", "mr duncan gray", "mr duncan shaw", "_ duncan sarah", "mr dundas sarah"
"j duncan smith" » "j duncan scott", "_ duncan smith"
"john duncan sir" » "john dunton sir", "john dunning sir", "john duncan i"

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: (("mr duncan sarah") OR ((("j duncan smith") OR ("john duncan sir")))).
• Removing quotes may allow a broader search: (( mr duncan sarah ) or ((( j duncan smith ) or ( john duncan sir )))).
• Adding a wildcard symbol may retrieve word variants: (("mr duncan sarah") or ((("j duncan smith") or ("john duncan sir"))))*.