Perhaps you should try some spelling variations:
"modified parameter estimation algorithms" » "modified parameter estimation algorithm", "modified parameter optimization algorithms", "modified parameter optimisation algorithm", "modified parameter estimates algorithms"
"modified df approximation algorithms" » "modified _ approximation algorithms", "modified one approximation algorithms", "modified time approximation algorithms", "modified adam approximation algorithms", "modified bi1 approximation algorithms"

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• Performing a fuzzy search may retrieve terms with similar spellings: (("modified df approximation algorithms") or ("modified parameter estimation algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified df approximation algorithms") OR ("modified parameter estimation algorithms"))*.
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