Perhaps you should try some spelling variations:
"modified rough approximation algorithm" » "modified rough approximation algorithms", "modified rough approximations algorithm", "modified one approximation algorithm"
"modified parameters estimation algorithm" » "modified parameter estimation algorithm", "modified parameter estimates algorithm", "modified parameter optimization algorithm"

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• Performing a fuzzy search may retrieve terms with similar spellings: (("modified parameters estimation algorithm") OR ("modified rough approximation algorithm"))~.
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