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

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• Performing a fuzzy search may retrieve terms with similar spellings: (("modified caging optimization algorithms") or ("modified objective approximation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified caging optimization algorithms") OR ("modified objective approximation algorithm"))*.
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