Perhaps you should try some spelling variations:
"modified dfdamverage approximation algorithms" » "modified average approximation algorithms"
"modified adam classification algorithm" » "modified a classification algorithm", "modified gas classification algorithm", "modified image classification algorithm", "modified df classification algorithm", "modified near classification 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: (("modified dfdamverage approximation algorithms") OR ("modified adam classification algorithm"))~.
• Removing quotes may allow a broader search: (( modified dfdamverage approximation algorithms ) or ( modified adam classification algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified dfdamverage approximation algorithms") or ("modified adam classification algorithm"))*.