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