Perhaps you should try some spelling variations:
"modified rough approximation algorithm" » "modified rough approximation algorithms", "modified rough approximations algorithm", "modified one approximation algorithm"
"modified parameter estimation algorithms" » "modified parameter estimation algorithm", "modified parameter optimization algorithms", "modified parameter optimisation algorithm", "modified parameter estimates algorithms"

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 parameter estimation algorithms") or ("modified rough approximation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified parameter estimation algorithms") OR ("modified rough approximation algorithm")).
• Removing quotes may allow a broader search: (( modified parameter estimation algorithms ) or ( modified rough approximation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified parameter estimation algorithms") or ("modified rough approximation algorithm"))*.