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