Perhaps you should try some spelling variations:
"modified df approximation algorithm" » "modified df approximation algorithms", "modified _ approximation algorithm", "modified one approximation algorithm", "modified time approximation algorithm", "modified adam approximation algorithm", "modified bi1 approximation algorithm"
"modified game optimization algorithm" » "modified game optimization algorithms", "modified game optimisation algorithm", "modified game estimation algorithm", "modified stage optimization algorithm", "modified qoe optimization algorithm", "modified market optimization algorithm", "modified male optimization algorithm", "modified adam optimization algorithm"

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