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