Perhaps you should try some spelling variations:
"modified coverage approximation algorithms" » "modified average approximation algorithms"
"modified charging aided algorithm" » "modified caging aided algorithm", "modified carbon aided algorithm", "modified charging adam algorithm", "modified charging driven algorithm", "modified charging winner algorithm", "modified learning aided algorithm", "modified charging pile 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 coverage approximation algorithms") OR ("modified charging aided algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified coverage approximation algorithms\") OR (\"modified charging aided algorithm\"))*".
• Removing quotes may allow a broader search: (( modified coverage approximation algorithms ) OR ( modified charging aided algorithm ))*.