Perhaps you should try some spelling variations:
"multi accident research : july 2012" » "multi current research : july 2012", "multi recent research : july 2012", "multi client research : july 2012", "multi accident research : july 2013"
"active vaccine research : july 2008" » "active medicine research : july 2008", "anti vaccine research : july 2008", "positive vaccine research : july 2008", "active vaccine research : july 2013", "active vaccine research : july 2020", "active vaccine research : july 2015"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"active vaccine research : july 2008\") OR (\"multi accident research : july 2012\"))~".
• Removing quotes may allow a broader search: (( active vaccine research : july 2008 ) OR ( multi accident research : july 2012 ))~.
• Adding a wildcard symbol may retrieve word variants: (("active vaccine research : july 2008") OR ("multi accident research : july 2012"))*.