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

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

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