Perhaps you should try some spelling variations:
parameters optimization » parameter optimization, parameter estimation
approximation algorithm » approximation algorithms
optimization algorithm » optimization algorithms, optimisation algorithm, estimation algorithm
one approximation » time approximation, _ approximation, rough approximations

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: (( parameters optimization algorithm ) OR ( one approximation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (( parameters optimization algorithm ) or ( one approximation algorithm ))*.