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