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