Perhaps you should try some spelling variations:
"modified parameter estimation algorithms" » "modified parameter estimation algorithm", "modified parameter optimization algorithms", "modified parameter optimisation algorithm", "modified parameter estimates algorithms"
"modified objective solution algorithm" » "modified objective evolutionary algorithm", "modified objective allocation algorithm", "modified objective evolution algorithm", "modified objective convolution 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 objective solution algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified parameter estimation algorithms") OR ("modified objective solution algorithm")).
• Removing quotes may allow a broader search: (( modified parameter estimation algorithms ) or ( modified objective solution algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified parameter estimation algorithms") or ("modified objective solution algorithm"))*.