Perhaps you should try some spelling variations:
"modified parameter optimisation algorithm" » "modified parameter optimization algorithm", "modified parameter estimation algorithm", "modified parameter optimization algorithms"
"modified policy estimation algorithms" » "modified policy estimation algorithm", "modified policy optimization algorithms", "modified policy approximation algorithms", "modified pose estimation algorithms", "modified motion estimation algorithms"

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 policy estimation algorithms") OR ("modified parameter optimisation algorithm"))~.
• Removing quotes may allow a broader search: (( modified policy estimation algorithms ) or ( modified parameter optimisation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified policy estimation algorithms") or ("modified parameter optimisation algorithm"))*.