Perhaps you should try some spelling variations:
"modified policy optimization algorithms" » "modified policy optimisation algorithm", "modified policy estimation algorithms", "modified policy estimation algorithm", "modified topology optimization algorithms"
"modified invasive ventilation algorithm" » "modified invasive estimation algorithm", "modified invasive estimation algorithms", "modified invasive evolution algorithm", "modified adaptive ventilation algorithm", "modified passive ventilation algorithm"

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

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