Perhaps you should try some spelling variations:
"modified orca approximation algorithm" » "modified orca approximation algorithms", "modified one approximation algorithm", "modified _ approximation algorithm", "modified time approximation algorithm"
"modified invasive convolution algorithms" » "modified invasive evolution algorithm", "modified invasive solution algorithm", "modified invasive ventilation algorithms", "modified passive convolution 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 invasive convolution algorithms") or ("modified orca approximation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified invasive convolution algorithms") OR ("modified orca approximation algorithm")).
• Removing quotes may allow a broader search: (( modified invasive convolution algorithms ) or ( modified orca approximation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified invasive convolution algorithms") or ("modified orca approximation algorithm"))*.