Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithms"
"machines learning estimation algorithm" » "machines learning emotion algorithm", "machines lighting estimation algorithm", "machine learning estimation algorithm", "active learning estimation algorithm", "mapping 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: (("machines learning estimation algorithm") OR ("modified multiobjective optimization algorithm"))~.
• Removing quotes may allow a broader search: (( machines learning estimation algorithm ) or ( modified multiobjective optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("machines learning estimation algorithm") or ("modified multiobjective optimization algorithm"))*.