Perhaps you should try some spelling variations:
"pull factor research : july 2009" » "pull factors research : july 2009", "pull sector research : july 2009", "pull actors research : july 2009", "pull factor research : july 2008", "pull factor research : july 2007", "pull factor research : july 2019"
"_ multifactor research : july 2006" » "_ multifactors research : july 2006", "_ multisector research : july 2006", "_ multiactors research : july 2006", "_ multifactor research : july 2008", "_ multifactor research : july 2007", "_ multifactor research : july 2013", "_ multifaceted research : july 2006"

Try widening your search to All Fields.

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• Performing a fuzzy search may retrieve terms with similar spellings: (("pull factor research : july 2009") or ("_ multifactor research : july 2006"))~.
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