Perhaps you should try some spelling variations:
"defined network optimisation algorithm" » "defined network optimization algorithms", "defined network estimation algorithm", "defined network estimation algorithms", "defined network optimization algorithm"
"modified df approximation algorithms" » "modified _ approximation algorithms", "modified one approximation algorithms", "modified time approximation algorithms", "modified adam approximation algorithms", "modified bi1 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 df approximation algorithms") or ("defined network optimisation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified df approximation algorithms") OR ("defined network optimisation algorithm")).
• Removing quotes may allow a broader search: (( modified df approximation algorithms ) or ( defined network optimisation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified df approximation algorithms") or ("defined network optimisation algorithm"))*.