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