Perhaps you should try some spelling variations:
"modified a approximation algorithms" » "modified _ approximation algorithms", "modified one approximation algorithms", "modified time approximation algorithms", "modified df approximation algorithms", "modified adam approximation algorithms"
"modified adamdamdaptive estimation algorithm" » "modified _damdamdaptive estimation algorithm", "modified dfdamdamdaptive estimation algorithm", "modified adamdamdamdaptive estimation algorithm"

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