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

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

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