Perhaps you should try some spelling variations:
"modified multiobjective approximation algorithms" » "modified multiobjective optimization algorithms"
"code learning method algorithm" » "code learning mom algorithm", "code learning methods algorithm", "code graining methods algorithm", "code learning emotion algorithm", "how learning method algorithm"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified multiobjective approximation algorithms") or ("code learning method algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified multiobjective approximation algorithms") OR ("code learning method algorithm"))*.
• Removing quotes may allow a broader search: (( modified multiobjective approximation algorithms ) or ( code learning method algorithm ))*.