Perhaps you should try some spelling variations:
"modified parameters optimization algorithm" » "modified parameter optimization algorithm", "modified parameter estimation algorithm", "modified parameters optimization algorithms", "modified parameters optimisation algorithm", "modified parameters estimation algorithm"
"modified rough approximation algorithm" » "modified rough approximation algorithms", "modified rough approximations algorithm", "modified one approximation 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 parameters optimization algorithm\") OR (\"modified rough approximation algorithm\"))~".
• Removing quotes may allow a broader search: (( modified parameters optimization algorithm ) OR ( modified rough approximation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified parameters optimization algorithm") OR ("modified rough approximation algorithm"))*.