Perhaps you should try some spelling variations:
estimation algorithmss » estimation algorithms, estimation algorithm, optimization algorithms
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
parameters estimation » parameter estimation, parameter estimates, parameter optimization
sphere optimisation » sphere estimation

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( parameters estimation algorithmss ) OR ( sphere optimisation algorithm ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( parameters estimation algorithmss ) OR ( sphere optimisation algorithm ))".
• Adding a wildcard symbol may retrieve word variants: (( parameters estimation algorithmss ) OR ( sphere optimisation algorithm ))*.