Perhaps you should try some spelling variations:
"modified allocation approximation algorithms" » "modified allocation optimization algorithms"
"modified aging optimized algorithms" » "modified aging optimized algorithm", "modified aging optimizer algorithms", "modified aging optimization algorithms", "modified caging optimized algorithms"

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 aging optimized algorithms") OR ("modified allocation approximation algorithms"))~.
• Removing quotes may allow a broader search: (( modified aging optimized algorithms ) or ( modified allocation approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified aging optimized algorithms") or ("modified allocation approximation algorithms"))*.