Perhaps you should try some spelling variations:
"modified objective optimization algorithm" » "modified multiobjective optimization algorithm", "modified objective optimization algorithms", "modified objective optimisation algorithm", "modified objective estimation algorithm"
"modified sphere estimation algorithmss" » "modified sphere estimation algorithms", "modified sphere estimation algorithm", "modified sphere optimization algorithms", "modified pose estimation algorithmss"

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• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified objective optimization algorithm\") OR (\"modified sphere estimation algorithmss\"))~".
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