Perhaps you should try some spelling variations:
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
over optimisation » _ optimisation
game optimization » stage optimization, market optimization, _ optimization
qoe optimization » _ optimization, stage optimization, _ optimisation

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