Perhaps you should try some spelling variations:
"modified parameter optimization algorithm" » "modified parameter optimization algorithms", "modified parameter optimisation algorithm", "modified parameter estimation algorithm", "modified parameters optimization algorithm"
"modified coverage approximation algorithms" » "modified average approximation algorithms"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified parameter optimization algorithm") OR ("modified coverage approximation algorithms"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified parameter optimization algorithm\") OR (\"modified coverage approximation algorithms\"))*".
• Removing quotes may allow a broader search: (( modified parameter optimization algorithm ) OR ( modified coverage approximation algorithms ))*.