Perhaps you should try some spelling variations:
"modified response estimation algorithms" » "modified response estimation algorithm", "modified response optimization algorithms", "modified response optimisation algorithm", "modified pose estimation algorithms", "modified response association algorithms"
"modified invasive approximation algorithms" » "modified passive approximation algorithms"

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• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified response estimation algorithms\") OR (\"modified invasive approximation algorithms\"))~".
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