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