Perhaps you should try some spelling variations:
"multiple options research : july 2009" » "multiple locations research : july 2009", "multiple positions research : july 2009", "multiple solutions research : july 2009", "multiple actions research : july 2009", "multiple optics research : july 2009", "multiple operations research : july 2009", "multiple options research : july 2008", "multiple options research : july 2007", "multiple options research : july 2019"
"multiple opinion research : july 2012" » "multiple positions research : july 2012", "multiple decision research : july 2012", "multiple ion research : july 2012", "multiple action research : july 2012", "multiple opinion research : july 2013"

Try widening your search to All Fields.

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