Perhaps you should try some spelling variations:
"modified passive estimation algorithmss" » "modified passive estimation algorithms", "modified passive optimization algorithms", "modified pose estimation algorithmss", "modified adaptive estimation algorithmss"
"modified parameter estimation algorithm" » "modified parameter estimates algorithm", "modified parameter optimization algorithm"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified passive estimation algorithmss\") OR (\"modified parameter estimation algorithm\"))~".
• Removing quotes may allow a broader search: (( modified passive estimation algorithmss ) OR ( modified parameter estimation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified passive estimation algorithmss") OR ("modified parameter estimation algorithm"))*.