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

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((qoe optimisation) OR (qoe optimization)) algorithm ) or ( sphere optimisation algorithms ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((qoe optimisation) OR (qoe optimization)) algorithm ) OR ( sphere optimisation algorithms )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((qoe optimisation) OR (qoe optimization)) algorithm ) or ( sphere optimisation algorithms ))".
• Adding a wildcard symbol may retrieve word variants: (( ((qoe optimisation) OR (qoe optimization)) algorithm ) or ( sphere optimisation algorithms ))*.