Perhaps you should try some spelling variations:
approximation algorithm » approximation algorithms
one approximation » time approximation, _ approximation, rough approximations
method algorithm » mom algorithm
modified one » modified male, modified near, modified orca
core using » care nursing

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((core using) OR (code using)) method algorithm ) or ( modified one approximation algorithm ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((core using) OR (code using)) method algorithm ) OR ( modified one approximation algorithm )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((core using) OR (code using)) method algorithm ) or ( modified one approximation algorithm ))".
• Adding a wildcard symbol may retrieve word variants: (( ((core using) OR (code using)) method algorithm ) or ( modified one approximation algorithm ))*.