Perhaps you should try some spelling variations:
national research » educational research
multi national » multinationals _
july 2009 » july 2008, july 2007, july 2006
july 2019 » july 2013, july 2015, july 2020
july 2011 » july 2013, july 2015, july 2020
july 2012 » july 2013

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: multi national research : ((((((july 2009) OR (july 2019))) OR (july 2011))) OR (july 2012))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "multi national research : ((((((july 2009) OR (july 2019))) or (july 2011))) or (july 2012))~".
• Adding a wildcard symbol may retrieve word variants: multi national research : ((((((july 2009) OR (july 2019))) or (july 2011))) or (july 2012))*.