Perhaps you should try some spelling variations:
approximation algorithm » approximation algorithms
ventilation algorithm » estimation algorithm, estimation algorithms, evolution algorithm
invasive ventilation » adaptive ventilation
seird approximation » time approximation, network approximation
modified invasive » modified passive
modified seird » modified near

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• Performing a fuzzy search may retrieve terms with similar spellings: (( modified invasive ventilation algorithm ) or ( modified seird approximation algorithm ))~.
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