Perhaps you should try some spelling variations:
"modified objective optimized algorithm" » "modified objective optimal algorithm", "modified objective optimization algorithm", "modified objective optimized algorithms", "modified objective optimizer algorithms"
"modified average approximation algorithms" » "modified coverage approximation algorithms"

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• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified objective optimized algorithm\") OR (\"modified average approximation algorithms\"))~".
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