Perhaps you should try some spelling variations:
approximation algorithm » approximation algorithms
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
seird approximation » time approximation, network approximation
qoe optimisation » qoe optimization, _ optimisation, game optimization
modified seird » modified near
modified qoe » modified male, modified _, modified bi1

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

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