Perhaps you should try some spelling variations:
"ra duncan sarah" » "ra duncan adam", "ra duncan gray", "ra duncan shaw", "_ duncan sarah", "mr duncan sarah", "j duncan sarah"
"jon duncan smith" » "jon duncan scott", "john duncan smith", "j duncan smith", "colin duncan smith"
"ian duncan smith" » "ian duncan scott", "brian duncan smith", "a duncan smith", "innes duncan smith"
"jon duncan sir" » "john duncan sir", "j duncan sir", "colin duncan sir", "jon 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: (("ra duncan sarah") OR ((((("jon duncan smith") OR ("ian duncan smith"))) OR ("jon duncan sir")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"ra duncan sarah\") or (((((\"jon duncan smith\") OR (\"ian duncan smith\"))) or (\"jon duncan sir\"))))".
• Removing quotes may allow a broader search: (( ra duncan sarah ) or ((((( jon duncan smith ) OR ( ian duncan smith ))) or ( jon duncan sir )))).
• Adding a wildcard symbol may retrieve word variants: (("ra duncan sarah") or ((((("jon duncan smith") OR ("ian duncan smith"))) or ("jon duncan sir"))))*.