Perhaps you should try some spelling variations:
accident research » current research, recent research, vaccine research
multi accident » multi client
june 2009 » june 2007, june 2008, june 2019
july 2011 » july 2013, july 2019, july 2020
july 2015 » july 2013, july 2020, july 2008
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 accident research : ((((june 2009) OR (((july 2011) OR (july 2015))))) OR (july 2012))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "multi accident research : ((((june 2009) or (((july 2011) OR (july 2015))))) or (july 2012))~".
• Adding a wildcard symbol may retrieve word variants: multi accident research : ((((june 2009) or (((july 2011) OR (july 2015))))) or (july 2012))*.