Perhaps you should try some spelling variations:
"verified network approximation algorithm" » "verified network approximation algorithms", "certified network approximation algorithm", "defined network approximation algorithm"
"modified parameters optimization algorithm" » "modified parameter optimization algorithm", "modified parameter estimation algorithm", "modified parameters optimization algorithms", "modified parameters optimisation algorithm", "modified parameters estimation algorithm"

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: (("verified network approximation algorithm") OR ("modified parameters optimization algorithm"))~.
• Removing quotes may allow a broader search: (( verified network approximation algorithm ) or ( modified parameters optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("verified network approximation algorithm") or ("modified parameters optimization algorithm"))*.