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

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• Performing a fuzzy search may retrieve terms with similar spellings: (( modified qoe optimization algorithms ) or ( modified time approximation algorithm ))~.
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