Perhaps you should try some spelling variations:
"poultry operations research : july 2009" » "policy operations research : july 2009", "forestry operations research : july 2009", "court operations research : july 2009", "poultry operations research : july 2008", "poultry operations research : july 2007", "poultry operations research : july 2019"
"bus operations research : july 2012" » "bus operators research : july 2012", "day operations research : july 2012", "bus operations research : july 2013"

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