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