Perhaps you should try some spelling variations:
"modified coverage approximation algorithms" » "modified average approximation algorithms"
"modified discursive convolution algorithms" » "modified discursive construction algorithms", "modified discursive evolution algorithm", "modified discursive solution 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 coverage approximation algorithms") OR ("modified discursive convolution algorithms"))~.
• Removing quotes may allow a broader search: (( modified coverage approximation algorithms ) or ( modified discursive convolution algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified coverage approximation algorithms") or ("modified discursive convolution algorithms"))*.