Perhaps you should try some spelling variations:
"modified notion approximation algorithms" » "modified network approximation algorithms", "modified time approximation algorithms", "modified one approximation algorithms"
"modified study solution algorithm" » "modified study evolution algorithm", "modified study convolution algorithms", "modified study evolutionary algorithm", "modified student solutions algorithm", "modified study evaluation 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 notion approximation algorithms") OR ("modified study solution algorithm"))~.
• Removing quotes may allow a broader search: (( modified notion approximation algorithms ) or ( modified study solution algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified notion approximation algorithms") or ("modified study solution algorithm"))*.