Perhaps you should try some spelling variations:
"modified df validation algorithm" » "modified df estimation algorithm", "modified df predation algorithm", "modified df estimation algorithms", "modified _ validation algorithm", "modified a validation algorithm", "modified adam validation algorithm", "modified bi1 validation algorithm"
"modified notion approximation algorithms" » "modified network approximation algorithms", "modified time approximation algorithms", "modified one approximation algorithms"

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: (("modified df validation algorithm") OR ("modified notion approximation algorithms"))~.
• Removing quotes may allow a broader search: (( modified df validation algorithm ) or ( modified notion approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified df validation algorithm") or ("modified notion approximation algorithms"))*.