Perhaps you should try some spelling variations:
"modified multiobjective estimation algorithm" » "modified multiobjective optimization algorithm"
"modified caging optimization algorithm" » "modified caging optimization algorithms", "modified caging optimisation algorithm", "modified caging estimation algorithms", "modified staffing optimization algorithm"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified multiobjective estimation algorithm") or ("modified caging optimization algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified multiobjective estimation algorithm") OR ("modified caging optimization algorithm")).
• Removing quotes may allow a broader search: (( modified multiobjective estimation algorithm ) or ( modified caging optimization algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective estimation algorithm") or ("modified caging optimization algorithm"))*.