Perhaps you should try some spelling variations:
"colin duncan i" » "john duncan i", "colin duncan _", "colin duncan m", "colin duncan c"
"ian duncan sarah" » "ian duncan adam", "ian duncan gray", "ian duncan shaw", "brian duncan sarah", "a duncan sarah", "innes duncan sarah"
"jon duncan sir" » "john duncan sir", "j duncan sir"

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 ((("jon duncan sir") OR ("colin duncan i")))).
• Removing quotes may allow a broader search: (( ian duncan sarah ) or ((( jon duncan sir ) or ( colin duncan i )))).
• Adding a wildcard symbol may retrieve word variants: (("ian duncan sarah") or ((("jon duncan sir") or ("colin duncan i"))))*.