Perhaps you should try some spelling variations:
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
rough approximation » rough approximations
one approximation » time approximation, _ approximation, rough approximations
qoe optimisation » qoe optimization, _ optimisation, game optimization

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• Performing a fuzzy search may retrieve terms with similar spellings: (( ((rough approximation) OR (one approximation)) algorithm ) or ( qoe optimisation algorithm ))~.
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