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