Perhaps you should try some spelling variations:
multiple locations » multiple options, multiple positions, multiple solutions
locations research » relations research, actions research, solutions research
vaccine research » medicine research
anti vaccine » ant vaccine, active vaccine, aids vaccine
july 2008 » july 2013, july 2020, july 2015
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: (( anti vaccine research : july 2008 ) OR ( multiple locations research : july 2012 ))~.
• Adding a wildcard symbol may retrieve word variants: (( anti vaccine research : july 2008 ) or ( multiple locations research : july 2012 ))*.