Perhaps you should try some spelling variations:
"modified passive ventilation algorithms" » "modified passive estimation algorithms", "modified passive estimation algorithm", "modified passive convolution algorithms", "modified adaptive ventilation algorithms", "modified invasive ventilation algorithms"
"modified invasive evolution algorithm" » "modified invasive solution algorithm", "modified invasive evolutionary algorithm", "modified invasive convolution algorithms", "modified invasive ventilation algorithm"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified passive ventilation algorithms") or ("modified invasive evolution algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified passive ventilation algorithms") OR ("modified invasive evolution algorithm")).
• Removing quotes may allow a broader search: (( modified passive ventilation algorithms ) or ( modified invasive evolution algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified passive ventilation algorithms") or ("modified invasive evolution algorithm"))*.