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