Perhaps you should try some spelling variations:
"multi national research : july 2009" » "multi educational research : july 2009", "_ multinational research : july 2009", "multinationals _ research : july 2009", "_ multinationals research : july 2009", "multi national research : july 2013", "multi national research : july 2012", "multi national research : july 2011"
"multiple options research : july 2006" » "multiple imputations research : july 2006", "multi option research : july 2006", "multiple operations research : july 2006", "multiple action research : july 2006", "multiple opinion research : july 2006", "multiple options research : july 2013", "multiple options research : july 2012", "multiple options research : july 2011"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("multiple options research : july 2006") or ("multi national research : july 2009"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("multiple options research : july 2006") OR ("multi national research : july 2009"))*.
• Removing quotes may allow a broader search: (( multiple options research : july 2006 ) or ( multi national research : july 2009 ))*.