Perhaps you should try some spelling variations:
"modified sphere optimization algorithms" » "modified sphere estimation algorithms", "modified sphere estimation algorithm", "modified sphere optimized algorithms", "modified stage optimization algorithms", "modified response optimization algorithms"
"modified objective optimisation algorithm" » "modified objective optimization algorithm", "modified multiobjective optimization algorithm", "modified objective estimation algorithm", "modified objective estimation algorithms"

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 optimisation algorithm") OR ("modified sphere optimization algorithms"))~.
• Removing quotes may allow a broader search: (( modified objective optimisation algorithm ) or ( modified sphere optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified objective optimisation algorithm") or ("modified sphere optimization algorithms"))*.