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