Perhaps you should try some spelling variations:
"multi vaccine research : june 2011" » "multi medicine research : june 2011", "anti vaccine research : june 2011", "multiple vaccines research : june 2011", "multi vaccine research : june 2013", "multi vaccine research : june 2014", "multi vaccine research : june 2010"
"multi factor research : june 2011" » "multi factors research : june 2011", "multi sector research : june 2011", "multi actors research : june 2011", "multi actor research : june 2011", "_ multifactor research : june 2011", "multi factor research : june 2013", "multi factor research : june 2014", "multi factor research : june 2010"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("multi vaccine research : june 2011") OR ("multi factor research : june 2011"))~.
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• Removing quotes may allow a broader search: (( multi vaccine research : june 2011 ) OR ( multi factor research : june 2011 )).
• Adding a wildcard symbol may retrieve word variants: (("multi vaccine research : june 2011") OR ("multi factor research : june 2011"))*.