Perhaps you should try some spelling variations:
"multiple opinion research : july 2009" » "multiple options research : july 2009", "multiple positions research : july 2009", "multiple decision research : july 2009", "multiple action research : july 2009", "multiple opinion research : july 2008", "multiple opinion research : july 2007", "multiple opinion research : july 2019"
"multi option research : july 2009" » "multi action research : july 2009", "multi optics research : july 2009", "multi actions research : july 2009", "multi location research : july 2009", "multi population research : july 2009", "multi ratios research : july 2009", "multi option research : july 2008", "multi option research : july 2007", "multi option research : july 2019"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("multiple opinion research : july 2009") or ("multi option research : july 2009"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("multiple opinion research : july 2009") OR ("multi option research : july 2009")).
• Removing quotes may allow a broader search: (( multiple opinion research : july 2009 ) or ( multi option research : july 2009 )).
• Adding a wildcard symbol may retrieve word variants: (("multiple opinion research : july 2009") or ("multi option research : july 2009"))*.