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 estimation algorithm" » "modified parameter estimation algorithm", "modified parameter estimates algorithm", "modified parameter optimization algorithm"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("verified network approximation algorithm") or ("modified parameters estimation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("verified network approximation algorithm") OR ("modified parameters estimation algorithm")).
• Removing quotes may allow a broader search: (( verified network approximation algorithm ) or ( modified parameters estimation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("verified network approximation algorithm") or ("modified parameters estimation algorithm"))*.