Perhaps you should try some spelling variations:
vaccine research » medicine research
mali climate » bali climate, daily climate, early climate
new vaccine » novel vaccine, anti vaccine
july 2006 » july 2008, july 2007, july 2009
july 2011 » july 2013, july 2015, july 2019
july 2012 » july 2013

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( new vaccine research : july 2006 ) or ( mali climate research : ((july 2011) OR (july 2012)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( new vaccine research : july 2006 ) OR ( mali climate research : ((july 2011) OR (july 2012)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( new vaccine research : july 2006 ) or ( mali climate research : ((july 2011) OR (july 2012)) ))".
• Adding a wildcard symbol may retrieve word variants: (( new vaccine research : july 2006 ) or ( mali climate research : ((july 2011) OR (july 2012)) ))*.