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