Perhaps you should try some spelling variations:
national research » educational research
options research » actions research, optics research, operations research
making options » naming options, making positions, trading options
mali national » bali national, malawi national, multi national
july 2009 » july 2008, july 2007, july 2019
july 2006 » july 2008, july 2007, july 2013

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( making options research : july 2009 ) or ( mali national research : july 2006 ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( making options research : july 2009 ) OR ( mali national research : july 2006 )).
• Adding a wildcard symbol may retrieve word variants: (( making options research : july 2009 ) or ( mali national research : july 2006 ))*.