Perhaps you should try some spelling variations:
optimisation algorithm » optimization algorithms, estimation algorithm
estimation algorithmss » estimation algorithm, optimization algorithms
estimation algorithms » estimation algorithm, optimization algorithms, approximation algorithms
_ optimisation » _ 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: (( sphere ((estimation algorithmss) OR (estimation algorithms)) ) OR ( _ optimisation algorithm ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( sphere ((estimation algorithmss) OR (estimation algorithms)) ) or ( _ optimisation algorithm ))~".
• Adding a wildcard symbol may retrieve word variants: (( sphere ((estimation algorithmss) OR (estimation algorithms)) ) or ( _ optimisation algorithm ))*.