Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithms"
"mapping learning estimation algorithm" » "mapping learning emotion algorithm", "mapping lighting estimation algorithm", "machine learning estimation algorithm", "enabling learning estimation algorithm"

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: (("mapping learning estimation algorithm") OR ("modified multiobjective optimization algorithm"))~.
• Removing quotes may allow a broader search: (( mapping learning estimation algorithm ) or ( modified multiobjective optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("mapping learning estimation algorithm") or ("modified multiobjective optimization algorithm"))*.