Perhaps you should try some spelling variations:
class research » crops research, classroom research
early climate » daily climate, energy climate, family climate
multi class » multiclass _
july 2015 » july 2013, july 2012, july 2020
july 2006 » july 2008, july 2007, july 2013
july 2009 » july 2008, july 2007, july 2019

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( multi class research : july 2015 ) or ( early climate research : ((july 2006) OR (july 2009)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( multi class research : july 2015 ) OR ( early climate research : ((july 2006) OR (july 2009)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( multi class research : july 2015 ) or ( early climate research : ((july 2006) OR (july 2009)) ))".
• Adding a wildcard symbol may retrieve word variants: (( multi class research : july 2015 ) or ( early climate research : ((july 2006) OR (july 2009)) ))*.