Perhaps you should try some spelling variations:
approximation algorithm » approximation algorithms
near approximation » one approximation, network approximation, _ approximation
modified near » modified seird, modified adam
using method » nursing methods, focusing method, using python
using metal » using real, nursing mental, using medical
code » core

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

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