Perhaps you should try some spelling variations:
optimized algorithm » optimized algorithms, optimizer algorithms
invasive estimation » invasive ventilation
modified invasive » modified passive
df optimized » _ optimized, _ optimize
modified df » modified _, modified adam, modified bi1

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( modified df optimized algorithm ) or ( modified invasive estimation algorithm ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( modified df optimized algorithm ) OR ( modified invasive estimation algorithm )).
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