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

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 _ optimization algorithm") OR ("modified adaptive ventilation algorithm"))~.
• Removing quotes may allow a broader search: (( modified _ optimization algorithm ) or ( modified adaptive ventilation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified _ optimization algorithm") or ("modified adaptive ventilation algorithm"))*.