Perhaps you should try some spelling variations:
"modified coverage approximation algorithms" » "modified average approximation algorithms"
"modified sales solution algorithm" » "modified sales evolution algorithm", "modified sales convolution algorithms", "modified sales evolutionary algorithm", "modified male solution algorithm", "modified traces solution algorithm", "modified saline solution algorithm", "modified water solution 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 sales solution algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified coverage approximation algorithms\") OR (\"modified sales solution algorithm\"))*".
• Removing quotes may allow a broader search: (( modified coverage approximation algorithms ) OR ( modified sales solution algorithm ))*.