Perhaps you should try some spelling variations:
"modified df optimisation algorithm" » "modified df optimization algorithms", "modified df estimation algorithm", "modified _ optimisation algorithm", "modified _ optimization algorithm", "modified qoe optimization algorithm", "modified adam optimisation algorithm", "modified bi1 optimisation algorithm"
"modified parameters estimation algorithms" » "modified parameter estimation algorithms", "modified parameter estimates algorithms", "modified parameter optimization algorithms", "modified parameters estimation algorithm", "modified parameters optimization algorithms", "modified parameters approximation algorithms"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified parameters estimation algorithms") or ("modified df optimisation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified parameters estimation algorithms") OR ("modified df optimisation algorithm")).
• Removing quotes may allow a broader search: (( modified parameters estimation algorithms ) or ( modified df optimisation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified parameters estimation algorithms") or ("modified df optimisation algorithm"))*.