Perhaps you should try some spelling variations:
"modified notion approximation algorithms" » "modified network approximation algorithms", "modified time approximation algorithms", "modified one approximation algorithms"
"powder using search algorithm" » "powder using source algorithm", "code using search algorithm", "boiler using search algorithm", "model using search algorithm", "powder using egarch algorithm", "powder nursing research algorithm", "powder using servo algorithm"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("powder using search algorithm") or ("modified notion approximation algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("powder using search algorithm") OR ("modified notion approximation algorithms")).
• Removing quotes may allow a broader search: (( powder using search algorithm ) or ( modified notion approximation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("powder using search algorithm") or ("modified notion approximation algorithms"))*.