Perhaps you should try some spelling variations:
"modified coverage approximation algorithms" » "modified average approximation algorithms"
"modified charging estimation algorithms" » "modified charging estimation algorithm", "modified charging optimization algorithms", "modified charging optimisation algorithm", "modified charging station algorithms", "modified caging estimation algorithms", "modified carbon estimation algorithms"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified coverage approximation algorithms\") OR (\"modified charging estimation algorithms\"))~".
• Removing quotes may allow a broader search: (( modified coverage approximation algorithms ) OR ( modified charging estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified coverage approximation algorithms") OR ("modified charging estimation algorithms"))*.