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