Perhaps you should try some spelling variations:
"_ optimization algorithm" » "_ optimization algorithms", "_ optimisation algorithm", "_ optimized algorithm"
"_ estimation algorithms" » "_ optimization algorithms", "_ optimisation algorithm", "_ approximation algorithms"
"risk estimation algorithm" » "pose estimation 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: (("risk estimation algorithm") OR ((("_ estimation algorithms") OR ("_ optimization algorithm"))))~.
• Removing quotes may allow a broader search: (( risk estimation algorithm ) or ((( _ estimation algorithms ) or ( _ optimization algorithm ))))~.
• Adding a wildcard symbol may retrieve word variants: (("risk estimation algorithm") or ((("_ estimation algorithms") or ("_ optimization algorithm"))))*.