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