Perhaps you should try some spelling variations:
"multiple generations research : july 2009" » "multi generation research : july 2009", "multimap generation research : july 2009", "multiple migrations research : july 2009", "multiple generation research : july 2009", "multiple generational research : july 2009", "multiple generating research : july 2009", "multiple generations research : july 2008", "multiple generations research : july 2007", "multiple generations research : july 2019"
"multi accident research : july 2012" » "multi current research : july 2012", "multi recent research : july 2012", "multi vaccine research : july 2012", "multi client research : july 2012", "multi accident research : 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: (("multi accident research : july 2012") OR ("multiple generations research : july 2009"))~.
• Removing quotes may allow a broader search: (( multi accident research : july 2012 ) or ( multiple generations research : july 2009 ))~.
• Adding a wildcard symbol may retrieve word variants: (("multi accident research : july 2012") or ("multiple generations research : july 2009"))*.