Perhaps you should try some spelling variations:
"modified passive estimation algorithmssss" » "modified passive estimation algorithms", "modified pose estimation algorithmssss", "modified adaptive estimation algorithmssss"
"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.

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