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

Try widening your search to All Fields.

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

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