Perhaps you should try some spelling variations:
optimization algorithms » optimisation algorithm, estimation algorithms, estimation algorithm
qoe optimization » game optimization, _ optimization, stage optimization
code control » mode control, case control, order control
modified qoe » modified male, modified _, modified bi1
methods » method

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( code control methods algorithm ) or ( modified qoe optimization algorithms ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( code control methods algorithm ) OR ( modified qoe optimization algorithms )).
• Adding a wildcard symbol may retrieve word variants: (( code control methods algorithm ) or ( modified qoe optimization algorithms ))*.