Perhaps you should try some spelling variations:
"multi factor research : june 2011" » "multi factors research : june 2011", "multi sector research : june 2011", "multi actors research : june 2011", "multi actor research : june 2011", "_ multifactor research : june 2011", "multi factor research : june 2014", "multi factor research : june 2010", "multi factor research : june 2012"
"multi option research : june 2013" » "multi opinion research : june 2013", "multi action research : june 2013", "multi optics research : june 2013", "multi location research : june 2013", "multi population research : june 2013", "multi ratios research : june 2013"

Try widening your search to All Fields.

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