Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithm"
"modified invasive ventilation algorithm" » "modified invasive estimation algorithm", "modified invasive estimation algorithms", "modified invasive evolution algorithm", "modified adaptive ventilation algorithm", "modified passive 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 invasive ventilation algorithm") or ("modified multiobjective optimization algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified invasive ventilation algorithm") OR ("modified multiobjective optimization algorithm")).
• Removing quotes may allow a broader search: (( modified invasive ventilation algorithm ) or ( modified multiobjective optimization algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified invasive ventilation algorithm") or ("modified multiobjective optimization algorithm"))*.