Perhaps you should try some spelling variations:
"modified staffing optimization algorithm" » "modified staffing optimization algorithms", "modified staffing optimisation algorithm", "modified staffing estimation algorithm", "modified caging optimization algorithm"
"modified invasive approximation algorithms" » "modified passive approximation 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 staffing optimization algorithm") OR ("modified invasive approximation algorithms"))~.
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