Perhaps you should try some spelling variations:
"multi factor research : july 2009" » "multi factors research : july 2009", "multi sector research : july 2009", "multi actors research : july 2009", "multi actor research : july 2009", "_ multifactor research : july 2009", "multi factor research : july 2008", "multi factor research : july 2019", "multi factor research : july 2006"
"multi option research : july 2007" » "multi opinion research : july 2007", "multi action research : july 2007", "multi optics research : july 2007", "multi location research : july 2007", "multi population research : july 2007", "multi ratios research : july 2007", "multi option research : july 2008", "multi option research : july 2013", "multi option research : july 2012"

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 factor research : july 2009") OR ("multi option research : july 2007"))~.
• Removing quotes may allow a broader search: (( multi factor research : july 2009 ) or ( multi option research : july 2007 ))~.
• Adding a wildcard symbol may retrieve word variants: (("multi factor research : july 2009") or ("multi option research : july 2007"))*.