Perhaps you should try some spelling variations:
"modified multiobjective approximation algorithms" » "modified multiobjective optimization algorithms"
"model using real algorithm" » "model using adam algorithm", "model using search algorithm", "code using real algorithm", "models nursing real algorithm", "powder using real algorithm", "model using metal algorithm", "model using raw 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 multiobjective approximation algorithms") OR ("model using real algorithm"))~.
• Removing quotes may allow a broader search: (( modified multiobjective approximation algorithms ) or ( model using real algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective approximation algorithms") or ("model using real algorithm"))*.