Perhaps you should try some spelling variations:
estimation algorithmssss » estimation algorithms, estimation algorithm
optimization algorithms » optimisation algorithm, estimation algorithms, estimation algorithm
parameter estimation » parameter estimates, parameter optimization
attribute » attributed, attributes

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: (( parameter estimation algorithmssss ) OR ( attribute optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (( parameter estimation algorithmssss ) or ( attribute optimization algorithms ))*.