Perhaps you should try some spelling variations:
optimization algorithm » optimization algorithms, estimation algorithm, optimized algorithm
optimisation algorithm » optimization algorithms, estimation algorithm
estimation algorithms » estimation algorithm, optimization algorithms, approximation algorithms
risk optimisation » _ optimisation, risk estimation

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: (( qoe ((optimization algorithm) OR (estimation algorithms)) ) OR ( risk optimisation algorithm ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( qoe ((optimization algorithm) OR (estimation algorithms)) ) or ( risk optimisation algorithm ))~".
• Adding a wildcard symbol may retrieve word variants: (( qoe ((optimization algorithm) OR (estimation algorithms)) ) or ( risk optimisation algorithm ))*.