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