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