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