Perhaps you should try some spelling variations:
optimisation algorithm » optimization algorithms, estimation algorithm
estimation algorithms » estimation algorithm, optimization algorithms, approximation algorithms
policy estimation » policy optimization, pose estimation, motion estimation
risk optimisation » _ optimisation, risk estimation

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( policy estimation algorithms ) or ( risk optimisation algorithm ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( policy estimation algorithms ) OR ( risk optimisation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (( policy estimation algorithms ) or ( risk optimisation algorithm ))*.