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

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 _ convolution algorithms") OR ("modified parameters estimation algorithms"))~.
• Removing quotes may allow a broader search: (( modified _ convolution algorithms ) or ( modified parameters estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified _ convolution algorithms") or ("modified parameters estimation algorithms"))*.