Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithms" » "modified multiobjective optimization algorithms", "modified multiobjective estimation algorithm", "modified multiobjective optimisation algorithm"
"modified sphere estimation algorithmss" » "modified sphere estimation algorithm", "modified sphere optimization algorithms", "modified sphere estimation algorithms", "modified sphere optimization algorithmss", "modified sphere optimisation algorithms", "modified pose estimation algorithmss"

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 sphere estimation algorithmss") OR ("modified multiobjective estimation algorithms"))~.
• Removing quotes may allow a broader search: (( modified sphere estimation algorithmss ) or ( modified multiobjective estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified sphere estimation algorithmss") or ("modified multiobjective estimation algorithms"))*.