Perhaps you should try some spelling variations:
"modified _ optimization algorithm" » "modified _ optimization algorithms", "modified _ optimisation algorithm", "modified _ estimation algorithm"
"modified parameters estimation algorithmss" » "modified parameters estimation algorithms", "modified parameters estimation algorithm", "modified parameters optimization algorithms", "modified parameter estimation algorithmss", "modified parameter estimates algorithmss", "modified parameter optimization algorithmss"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified _ optimization algorithm") or ("modified parameters estimation algorithmss"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified _ optimization algorithm") OR ("modified parameters estimation algorithmss")).
• Removing quotes may allow a broader search: (( modified _ optimization algorithm ) or ( modified parameters estimation algorithmss )).
• Adding a wildcard symbol may retrieve word variants: (("modified _ optimization algorithm") or ("modified parameters estimation algorithmss"))*.