Perhaps you should try some spelling variations:
"modified invasive ventilation algorithms" » "modified invasive estimation algorithm", "modified invasive convolution algorithms", "modified adaptive ventilation algorithms", "modified passive ventilation algorithms"
"modified objective estimation algorithms" » "modified objective estimation algorithm", "modified objective optimization algorithms", "modified objective optimisation algorithm", "modified objective allocation algorithms"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified invasive ventilation algorithms") OR ("modified objective estimation algorithms"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified invasive ventilation algorithms\") OR (\"modified objective estimation algorithms\"))".
• Removing quotes may allow a broader search: (( modified invasive ventilation algorithms ) OR ( modified objective estimation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified invasive ventilation algorithms") OR ("modified objective estimation algorithms"))*.