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