Perhaps you should try some spelling variations:
"multi option research : july 2019" » "multi opinion research : july 2019", "multi action research : july 2019", "multi optics research : july 2019", "multi location research : july 2019", "multi population research : july 2019", "multi ratios research : july 2019", "multi option research : july 2013", "multi option research : july 2012", "multi option research : july 2015"
"multi labor research : july 2009" » "multi water research : july 2009", "multi prior research : july 2009", "multi layer research : july 2009", "multi label research : july 2009", "multi factor research : july 2009", "multi labor research : july 2008", "multi labor research : july 2007", "multi labor research : july 2006"

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 option research : july 2019") OR ("multi labor research : july 2009"))~.
• Removing quotes may allow a broader search: (( multi option research : july 2019 ) or ( multi labor research : july 2009 ))~.
• Adding a wildcard symbol may retrieve word variants: (("multi option research : july 2019") or ("multi labor research : july 2009"))*.