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

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