Perhaps you should try some spelling variations:
"modified coverage approximation algorithms" » "modified average approximation algorithms"
"modified male evaluation algorithm" » "modified male evolution algorithm", "modified male estimation algorithm", "modified male solution algorithm", "modified based evaluation algorithm", "modified large evaluation algorithm", "modified time evaluation 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 male evaluation algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified coverage approximation algorithms\") OR (\"modified male evaluation algorithm\"))".
• Removing quotes may allow a broader search: (( modified coverage approximation algorithms ) OR ( modified male evaluation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified coverage approximation algorithms") OR ("modified male evaluation algorithm"))*.