Perhaps you should try some spelling variations:
"modified time approximation algorithm" » "modified time approximation algorithms", "modified one approximation algorithm", "modified _ approximation algorithm", "modified bi1 approximation algorithm", "modified male approximation algorithm"
"modified topology estimation algorithms" » "modified topology estimation algorithm", "modified topology optimization algorithms", "modified topology optimisation algorithm"

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 topology estimation algorithms") or ("modified time approximation algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified topology estimation algorithms") OR ("modified time approximation algorithm")).
• Removing quotes may allow a broader search: (( modified topology estimation algorithms ) or ( modified time approximation algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified topology estimation algorithms") or ("modified time approximation algorithm"))*.