Perhaps you should try some spelling variations:
"modified topology optimization algorithms" » "modified topology optimisation algorithm", "modified topology estimation algorithms", "modified topology estimation algorithm"
"modified coverage approximation algorithms" » "modified average approximation algorithms"

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