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"
"anti vaccine research : july 2011" » "anti medicine research : july 2011", "ant vaccine research : july 2011", "active vaccine research : july 2011", "aids vaccine research : july 2011", "anti vaccine research : july 2013", "anti vaccine research : july 2015", "anti vaccine research : july 2019"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("anti vaccine research : july 2011") OR ("multi accident research : july 2012"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"anti vaccine research : july 2011\") OR (\"multi accident research : july 2012\"))".
• Removing quotes may allow a broader search: (( anti vaccine research : july 2011 ) OR ( multi accident research : july 2012 )).
• Adding a wildcard symbol may retrieve word variants: (("anti vaccine research : july 2011") OR ("multi accident research : july 2012"))*.