Perhaps you should try some spelling variations:
accident research » current research, recent research, vaccine research
multi accident » multi client
july 2009 » july 2008, july 2007, july 2019
june 2009 » june 2007, june 2008, june 2019
july 2012 » july 2013
july 2006 » july 2008, july 2007, 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 accident research : ((((((july 2009) OR (june 2009))) OR (july 2012))) OR (july 2006))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "multi accident research : ((((((july 2009) OR (june 2009))) or (july 2012))) or (july 2006))~".
• Adding a wildcard symbol may retrieve word variants: multi accident research : ((((((july 2009) OR (june 2009))) or (july 2012))) or (july 2006))*.