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