Perhaps you should try some spelling variations:
estimation algorithmssssss » estimation algorithms, estimation algorithm
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
parameter estimation » parameter estimates, parameter optimization
policy optimisation » policy optimization, topology optimization

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 optimisation algorithm ) OR ( parameter estimation algorithmssssss ))~.
• Adding a wildcard symbol may retrieve word variants: (( policy optimisation algorithm ) or ( parameter estimation algorithmssssss ))*.