Perhaps you should try some spelling variations:
optimisation algorithms » optimisation algorithm, optimization algorithms, estimation algorithm
estimation algorithms » estimation algorithm, optimization algorithms, optimisation algorithm
invasive estimation » invasive ventilation
modified invasive » modified passive

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( modified invasive estimation algorithms ) OR ( modified _ optimisation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (( modified invasive estimation algorithms ) or ( modified _ optimisation algorithms ))*.