Perhaps you should try some spelling variations:
"modified location optimization algorithm" » "modified location optimization algorithms", "modified location optimisation algorithm", "modified location estimation algorithm", "modified allocation optimization algorithm", "modified static optimization algorithm", "modified carbon optimization algorithm"
"modified average approximation algorithms" » "modified coverage approximation 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 average approximation algorithms") OR ("modified location optimization algorithm"))~.
• Removing quotes may allow a broader search: (( modified average approximation algorithms ) or ( modified location optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified average approximation algorithms") or ("modified location optimization algorithm"))*.