Perhaps you should try some spelling variations:
"modified dfverage approximation algorithms" » "modified average approximation algorithms", "modified _verage approximation algorithms", "modified adamverage approximation algorithms", "modified bi1verage approximation algorithms"
"modified df evolution algorithm" » "modified df solution algorithm", "modified df evolutionary algorithm", "modified df convolution algorithms", "modified _ evolution algorithm", "modified co evolution algorithm", "modified adam evolution algorithm", "modified bi1 evolution 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 df evolution algorithm") OR ("modified dfverage approximation algorithms"))~.
• Removing quotes may allow a broader search: (( modified df evolution algorithm ) or ( modified dfverage approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified df evolution algorithm") or ("modified dfverage approximation algorithms"))*.