Perhaps you should try some spelling variations:
estimation algorithmss » estimation algorithm, optimization algorithms
estimation algorithms » estimation algorithm, optimization algorithms, optimisation algorithm
policy estimation » policy optimization, pose estimation, motion estimation
sphere estimation » pose estimation

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: (( policy estimation algorithms ) OR ( sphere estimation algorithmss ))~.
• Adding a wildcard symbol may retrieve word variants: (( policy estimation algorithms ) or ( sphere estimation algorithmss ))*.