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

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 policy estimation algorithms") or ("modified multiobjective estimation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified policy estimation algorithms") OR ("modified multiobjective estimation algorithm")).
• Removing quotes may allow a broader search: (( modified policy estimation algorithms ) or ( modified multiobjective estimation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified policy estimation algorithms") or ("modified multiobjective estimation algorithm"))*.