Perhaps you should try some spelling variations:
"modified coverage approximation algorithms" » "modified average approximation algorithms"
"modified geochemical solution algorithm" » "modified chemical solution algorithm", "modified geochemical evolution algorithm", "modified geochemical convolution algorithms", "modified geochemical evolutionary algorithm"

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 geochemical solution algorithm\") OR (\"modified coverage approximation algorithms\"))~".
• Removing quotes may allow a broader search: (( modified geochemical solution algorithm ) OR ( modified coverage approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified geochemical solution algorithm") OR ("modified coverage approximation algorithms"))*.