Perhaps you should try some spelling variations:
classroom research » class research
accident research » current research, recent research, vaccine research
multi classroom » quality classroom
multi accident » multi client
july 2007 » july 2008, july 2013, july 2012

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( multi classroom research : july 2007 ) or ( multi accident research : july 2007 ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( multi classroom research : july 2007 ) OR ( multi accident research : july 2007 )).
• Adding a wildcard symbol may retrieve word variants: (( multi classroom research : july 2007 ) or ( multi accident research : july 2007 ))*.