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

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

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