Perhaps you should try some spelling variations:
approximation algorithm » approximation algorithms
market optimization » parameter optimization, market capitalization
one approximation » time approximation, _ approximation, rough approximations
game optimization » stage optimization, qoe optimization, _ 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: (( one approximation algorithm ) OR ( ((market optimization) OR (game optimization)) algorithm ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( one approximation algorithm ) or ( ((market optimization) OR (game optimization)) algorithm ))~".
• Adding a wildcard symbol may retrieve word variants: (( one approximation algorithm ) or ( ((market optimization) OR (game optimization)) algorithm ))*.