Perhaps you should try some spelling variations:
"multiple opinion research : july 2006" » "multiple options research : july 2006", "multiple positions research : july 2006", "multiple decision research : july 2006", "multiple opinion research : july 2008", "multiple opinion research : july 2007", "multiple opinion research : july 2013"
"multi action research : july 2009" » "multi national research : july 2009", "multi actor research : july 2009", "multi option research : july 2009", "multi location research : july 2009", "multi action research : july 2008", "multi action research : july 2007", "multi action research : july 2019"

Try widening your search to All Fields.

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• Performing a fuzzy search may retrieve terms with similar spellings: (("multiple opinion research : july 2006") or ("multi action research : july 2009"))~.
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